FAQs relating to winterizing and maintenance of heating systems

FAQs relating to winterizing and maintenance of heating systems

Q: General comments on pro/con re draining a baseboard hot water system over the winter in a vacant house? 2 story with some plaster walls.
A: The concern with draining the system is that the pipes house will get below freezing temperatures. The water in any part of the house will expand and could burst pipes, fixtures, ect. All water pipes would need to be completely drained and left open to prevent water from gathering in the pipes and possible freeze-up. If the hydronic heating system is drained, next year when it goes back on, good practice will need to be followed to assure that all air is purged, etc. I would recommend contacting a heating and plumbing professional to assure that nothing is overlooked. P.S. During the winter time, Red leaves the heat on at the summer house. Red just turns the thermostat down so not to use up to much energy and keep the cost down. But high enough to keep pipes from freezing.


Q: I have a Federal boiler with a Bell & Gossett series 100 pump on it that runs the water through the pipes in my heating system through the house. In the winter time when I start using the heater there is a seperate switch to turn on the series 100 pump. The question I have is why would this pump need to run all the time and should it run from October through February? If that is the way it is designed that’s okay I just wanted to know if there was some shut-off switah that was not installed in the system.
A: Running the pump throughout the heating season is one way to operate the system. It provides flow all the time, so there may be less noise due to start-up, and you are using the residual heat from the boiler after it shuts down. More often, the pump starts when the thermostat calls for heat. Ask local Bell & Gossett dealer about our pump control packages if you want to change it. Having a switch near the pump is a good idea if someone must service the pump.


Q: I have a 100,000 BTU propane boiler servicing a single zone baseboard heating system in the house this has 40,000 BTU approx excess capacity. I would like to take the chill out of the basement using a fan assisted coil unit. Can you recommend a suitable unit and advise if I will need another circ pump and zone valve. The volume of the basement is 40 x 40 x 12 and stays at 45 to 55 degrees summer and winter.
A: If you are sure that the existing boiler has extra capacity, then you can easily hook up another terminal (of any kind) to heat the basement. If your existing pump can handle the increased flow, you could simply install the new unit with an electric zone valve. If the existing pump is on the small side, add a separate zone with pump and thermostat to heat the basement. Ask the people at our local B&G representative about adding B&G Flo-Controls. These devices protect the zone from unwanted heat due to gravity circulation into the idle zone. You may not need them if the basement zone elevation is lower thn the source of hot water.


Q: We have a steam radiator system in a 90-year-old house. On our 3rd floor bedroom when the steam starts to come up we are treated to bangs and clangs galore. This winter the heat emanating from the radiator diminished, then quit. Today, my husband put on a new air vent, and fiddled with the valve, but there was no improvement. Then he disconnected the radiator, turned up the heat, and we watched. We heard gurgles and burps, but no steam. Then I jiggled the pipe (it runs down through the flooring, then nearly horizontal through kneewall/ attic space, then down to the basement). Then loud gurgles, then the pipe spit up about two cups of water. Then steam came whooshing out! We are warm again. How do you explain this and what do you recommend for maintenance?
A: Based on what you told us, you have a one-pipe steam system. (Only one pipe connection, and it’s at the bottom of the radiator, an air vent on the other side.) It sounds like that “nearly horizontal” pipe run is the culprit in this mystery. It’s supposed to be pitched so that condensate from your radiator drains back to the boiler, even though steam is going the opposite way in the same pipe toward the radiator. Suppose that vertical leg leading to the radiator dropped a little so that the horizontal leg was pitched away from the boiler. Water could accumulate in the horizontal leg, and block the steam flow. If your “jiggling” resulted in lifting the pipe so that some of the trapped water drained back, then the difference in pressure between the steam and the atmosphere could blow the remaining water (two cups) out of the pipe, and you have heat. If this is the case, then the solution is to insure that the pipe stays pitched properly. There may be other factors we haven’t discussed, so it would be wise to have a qualified contractor look at the system.


Q: We have a old house, built about 1905, that has an American Radiator Hot water boiler system. The system has alway been a gravity recirculating system, another words, no pump. The house is large, about 3500 square feet, not including basement. There are three stories. Basement has no radiators. First floor has four radiators, second has four and third floor has three. Both the supply and return pipes, all of which are threaded steel pipe, at the boiler are 4″, though they are only that size for a few feet until they split into the four risers and returns. The risers/returns are sized from 1 1/4 to 2″. My question is…How do I size a pump and what controls do I need to have to make this pump work most effectively. Can I use a 2″ flanged pump? What is meant by “feet of head” in a two pipe system? Do I install this on the supply or return side.
A: This is such a common question that we have worked up some example problems which we cover in our “School of Living Comfort” hydronics design seminar. We go into a lot of detail about the science and the art of making this kind of conversion. It’s that word “art” that causes the problem here, because there’s a lot of detail to consider, and it’s impossible to cover all that in this short reply. If you contact the Bornquist, Inc. people, they can arrange for you to attend one of our seminars, free of charge. That way, you’ll get the whole story. If you can’t make it, here are some shorter answers to your specific questions. A 2″ pump would certainly be in the right ball park, since any pump will provide a lot more “head” than the gravity system provided, and consequently, you don’t need such large diameter pipes. As to the exact sizing of the pump, that requires a little more detail. Come to the seminar, or talk to Bornquist for specifics. “Head” in referring to pumps, is the amount of mechanical energy that the pump can put into the water to make it flow through the pipes at an acceptable rate. Think of head as foot -pounds of energy per pound of water. Each pump has its own head vs flow capability curve. Always install the pump so that it is pumping away from the point where the compression tank connects to the system. (That’s another detail we cover in the seminar–sizing of a new closed tank to replace the old open or closed tank your system may have.) Since the tank is often connected at the boiler, this amounts to pumping away from the boiler, or putting the tank on the supply pipe. Once again, it’s a bit more subtle than that, and if you can get to the seminar, we can clear up a lot of misunderstandings.


Q: I recently installed a new high-efficiency boiler in my house. The old boiler had 2 supply and return lines going in and out of the old boiler; each line has a B&G PR series pump. The new boiler has only 1 return and 1 supply outlet so the 2 supply and return lines had to be teed into the new boiler. Since the new boiler has been installed I can no longer get any heat out of two basement radiators that are at the end of each loop. I gutted the 2 check-valves and this helps a bit but I still can’t get hot water completely through the two end radiators. If I shut down one of the loops I can get hot water through the end radiator on the open loop.
A: A couple of things could be happening to explain why you’re not getting heat at the end of those loops. Call our representative, to help find a qualified contractor to help you solve this. Here are a couple of things to check. 1. Is the new boiler big enough? If it doesn’t have enough heating capacity, the end radiators won’t get hot. Since you can get heat when you shut off one loop, this may be the case. 2. You could have air trapped in the radiators. If the new boiler has a lot more pressure drop than the old one had, there may not be enough velocity in those radiators to pick up the air and bring it to the point of air separation.


Q: I have a gas boiler (radiator heat) with two B & G circulator pumps/boosters. The main circulator was here when I moved in 21 years ago (the house & boiler are 45 years old) and has the following noted: 17 amps, 115v, 11/12 hp, Ser # 101-5-1-M, 1725 rpm The other circulator was installed about 19 years for the second floor attic conversion (2 zone heat) and has the following: Series # 100, 106189, 225-245 degrees. I am looking into purchasing a backup generator and need to know the recommended start up and continuous running amps/watts for each circulator.
A: Both circulators should have very similar Amp and Watt input values. The locked rotor (start up) Amps will be in the 12.0 Amp range. The continuous run conditions will be approximately 1.7Amps/130 Watts.


Q: I am having a little trouble with my Hot water baseboard heat. I have a 2-story home that has 2 zones. 1 upstairs & 1 down. I recently was getting a lot of noise from my impeller area. I talked to a local supply house and we decided to remove & bring my motor/pump assembly in for inspection. We found the motor to be tired. We replaced the motor, bearing assembly, and impeller (all B&G parts). Since then, I have been having trouble getting heat to flow to the upstairs. I find that I get heat to the upstairs, but that there is no flow. I have purged the lines for air, and also, turned off the downstairs zone, forcing the system to circulate only the upstairs (I will call it zone 2). As long as zone 1 is off, I get great circulation through zone 2. When I open zone 1, zone 1 gets all the circulation. Is there a simple procedure I can use to balance the flow between the 2 zones?
A: You say you’re getting heat, but you have no flow. I’m not sure how you’re doing that or determining it. But based on the information you’ve included, I’d say that when the bearing assembly was replaced, that a balancing valve must have been closed to service the pump. Something had to have happened when the pump was replaced that upset the balance between the two zones, assuming there was no problem before. Somehow zone 2 now has a much greater pressure drop than before. To balance the system you have to determine the flow rate you require in each zone. Then you need to determine the pressure drop through each zone when the valves are open. Finally, you would ideally add pressure drop to the zone with the lower pressure drop to equal the pressure drop of the higher-pressure drop zone through the use of a balancing valve. To make it simpler, look at zone 2, and ask yourself what you can do to lower the pressure drop in that zone. If that does not balance the system, look at where you can add pressure drop to zone one until the two zones are equal. Retrace what you did before you replaced the bearing assembly, I’m willing to bet that is where the trouble occurred – a valve accidentally got closed and was not returned to it’s original position. Once you do that, I’m sure the problem will jump out at you. If none of these works, ask the local representative to stop by.


Q: While on vacation the water company shut off our water (long story). The water ran out of our operating Slc-30 circulator pump. A neighbor heard the noise from outside our house (sucking air, burning the pipes/pump) He turned it off. The plumber replaced the side pipes but thought the pump was still good. When running, it made a loud humming noise. He came back out said the pump was bad and not worth re-building. He replaced the pump, now the same noise is louder and we have to turn off the pump at night. He came out again and flushed the lines, still the same noise. He says something broke off and is in the system. Now he wants to charge us by the hour to clean out the lines. Do you know what is causing the hum, for 5 years we never heard the pump inside and it working perfectly? This has become very expensive and after $500.00 we are thinking of turning off the system and wasting water in our one story house to get hot water.
A: Something in your system must have change to cause the humming sound. There are a lot of unknown facts in your letter. Why did the city turn your water off? Did the system pressure change? Did the pipes in your system change in diameter or type? Did the plumber replace the SLC with a comparable circulator? Is there a pipe rubbing on a beam somewhere? These all could have an effect on your system that is causing the noise. Contact your local B&G representative.


Q: When weather is real cold in uninsulated old house, with one pipe steam,is it unusual for boiler to cycle off presutrol and not reach temp. after max pressure is reached ,what is normal leak down time for pressure to drop to low cut in. If fire is to large a nozzele will this cause to run off presurtrol and not reach temp. Only a few degrees lower than normal . Usually run at 72 but with 5 degree weather settel for 68 degrees.
A: A short cycling boiler in a one pipe steam system is often caused by end of main vents that are no longer working. As steam pressure builds, air in the system can’t escape through the vent, so the burner shuts off on high pressure long before steam gets to the radiators. See our local representative for help in getting those main line vents replaced.


Q: I have a Hydotherm furnace with a B&G 100 series pump. The house is piped for two heating loops, using zone valves. I have baseboard units in all rooms except for one which has original equipment. An array of baseboard convectors piped in series and stacked in a loop. These are connected to the main heating loop with scoop tee’s. After recently replacing the bearing assembly on the pump and bleeding as much air from the system as I could, I get no heat from this unit. All other rooms have baseboard units in series, NO scoop tees and heat up fine. Could this assembly be air bound? How can I solve this? Should I cut the loop between the scoop tees and insert a valve to force the hot water in this unit?
A: If the system worked before, it ought to work again, especially if the only change you made was a new bearing assembly for the pump. If you have manual air vents on the convector assembly, try venting the air. Restore the system pressure by using your pressure reducing valve to add more water after the venting.


Q: I have an American Standard G29,Series 7BN-J6 boiler.All my parts are B&G SA11/4 flow control valve;SA 3/4 flow control valve; ATF Airtrol valve below expansion tank;2 series 100 circulating pumps up and downstairs;Relief valve 175 set at 30lbs and inlet is3/4;Can’t read valve where water comes in from outside source because of drip from another pipe above separate from heating system.My question finally is that the relief valve goes off and releases steam and water for a couple minutes and what is causing this? The system has worked fine for 27 years.Shouldn’t I see the Temp drop in a couple minutes when the pump kicks on. The temp is high as 220degrees but gauge doesn’t go over 32lbs.Is it full of sludge?How do you drain it? The lines were just bled twice. Lots of air first.
A: From what you’ve given me, I’d say that you have a waterlogged tank. So lets get the system back to where it needs to be first. Let the sytem cool down to below 100 degrees. Ensure that the supply valve from the city is closed. Now open the Airtrol Tank Fitting vent screw until the water level returns to normal. Assuming the correct size ATF is installed, drain until no water comes out. Now you are back to the proper air to water ratio in the tank. Now for why you lost your original air charge. When you bled the air out of your system, you lost the room you had for the water to expand as it heated up. Figuring how the air got from the tank into the system is not as important as ensuring that once it is in the system that it is returns to the tank and remains there. The ATF should ensure that the air remains in the tank. So you might want to check that. Next, to ensure that any air in the system goes to the tank, check your air separator. You never mentioned one. So if you don’t have one, I’d recommend an Inline Air Separator or an Enhanced Air Separator. See your local rep to determine which one would be the best for your system based of effectiveness and cost. Also, make sure that you have no automatic air vents in your system. Automatic air vents are used with pre-charged air tanks. For the rest of your questions, I can not tell you if the temperature should drop until I know where you’re looking at the temperature. To drain your system, ensure that the city water supply is close, open the drain valve. Opening a vent will help drain the system. To fill the system, close the drain, open the city supply, use a Pressure Reducing Valve. Bleed out the air through the vents. Open the tank fitting vent until you see water come out. Now you have the proper charge. To clean your system, ask your local supply warehouse for what would be the most effective materials based on your system. Make sure that he knows about the pumps seals so that there is not a compatability problem. However, you probably will get rid of most foreign materals when you drain the system. If the system is truely closed, draining it will introduce oxygen, hence corrosion, so you don’t want to do it unless you have to.


Q: I have never been able to get hot water to one radiator upstairs; it’s the furthest from the pump. I have bleed the system countless times and can never get Hot water up there. Any suggestions? My house is 50 years old, but the system is only 20. I am thinking a small separate in-line booster pump in the line going upstairs from the crawl space might be a good fix? Any suggestions?
A: If you have tried to bleed air out of that radiator, and you don’t get any air, then the most likely cause is inadequate balance. Probably some of your closer radiators are getting far more flow than they need, starving that farthest one. Install a Bell & Gossett balancing valve in the closer circuits to reduce flow there and force the water out to the farthest one. If you do get air every time you bleed that farthest radiator, then you have an inadequate air separator or compression tank system. This could easily tie in to the system pressurization problem you brought up earlier. Our local B&G representative. has some excellent technical material that covers these problems. Ask him for TEH 1196, Air Management.


Q: We have a Series SLC-25 circulator that was in place when we purchased out house. We don’t know anything about it. We were told by a neighbor that it gives you hot water as soon as you turn on the tap. We’ve noticed that is not the case. There is no noise of vibration coming from it, however, the unit itself is always hot. We located a small knob on the side of the unit, but are unsure about which direction to turn it. It appears to be a fairly expensive item and we would like for it to work. Also… there is a 110 plug configuration that concerns us. The unit is plugged in and we have concerns about safety.
A: It should be a bronze bodied pump. It’s designed to recirculate hot water through the system so you don’t have stagnant, cool water after a period of no demand. The pump may be hot because it’s installed so close to the water heater. If it’s not pumping, check to insure that power is available in that circuit. The knob you see is the speed setting. Turn it to position #1, the highest speed, then feel the pipe coming back from the system, if it heats up, the pump is working properly. If it doesn’t, call the Bell & Gossett representative nearest you. You can look them up on our web site, or in the yellow pages. About the electrical connection, if it doesn’t look right to you, by all means call an electrician right away.


Q: I live in an old house heated by hot water radiators driven by an oil-fueled Columbia boiler with a circulating pump. It was installed in 1976. The house was previously heated by a coal furnace. In the last few years, there have been more and more frequent problems with getting all the radiators heated. Those on the end of the water circulation path (as told by the service technician) go cold when the weather gets a bit warmer and the furnace doesn’t run as frequently. They consequently would not heat up when the weather got colder again. In the last 2 years, usually only one radiator will be hot û the one that is at the beginning of the circulation path. The only way to get most (or all, if we are lucky) of the radiators hot is to drain the entire system and refill it. When done, the furnace will run consistently and all the radiators will be heat up for a 1-4 days. They will all gradually cool off, and the furnace will only in 5-minute bursts regardless of what the thermostat (also, original from 1976) is set at. We can get the one radiator at the beginning of the circulation path hot by bleeding it. It is the only radiator in the house that has its own bleeder valve. There is a ôMaid OÆMistö valve on a pipe in the attic that is supposed to vent out the air for the rest of the system. This has been replaced a number of times the last few years. I just wonder what can be the cause of these more and more frequent heating problems with faulty aquastat, bad thermostat, poor water circulation, weak/old boiler?
A: It sounds a lot like an air problem that gets progressively worse as time goes on. If you refill the whole system, you can get heat throughout, so the pump and boiler sound OK. That vent up in the attic just isn’t designed to control air as it should. The details are a bit lengthy for the internet, but a qualified contractor could provide the air separator you need and take a look at the existing tank to make sure it’s right too. Contact your local representative for this detailed help. You can find them on the web.


Q: Let me paint you the picture. I live in a Colonial style house of approx. 1600 sq. ft. built in the 1941. The heating system is single zone hydronic and employs a 150,000 BTU gas fired boiler circa 1977. The circulator pump is a B&G series 100 (other label markings include FW and 142 if this helps). The piping system starts out at 1 1/4″ and routes to the in-wall cast iron radiators on each floor. My problem is that when the system is cool (e.g. warm days/cool nights in spring and fall) and the thermostat calls for heat, the system takes about 40 minutes for the radiators to warm up at all; obviously an inefficient way to raise the temp by only a few degrees. I have noticed that even when the boiler runs (circulator runs too) for a while the delta temperature from the inlet to the outlet of the boiler is negligible. I theorize that the flow rate through the boiler it too high, not allowing sufficient heat transfer. Does it make sense for me to try a lower GPM circulator pump? If so, any suggestions? Does my theory hold water, or is this Electrical Engineer all wet? (No pun intended…. O.K. maybe a little). Also, do you know where I can get the curves for this pump? I couldn’t find them for this model on your site.
A: I think that the keyword in your story is cast iron. It takes a while to heat up all that thermal mass, and that’s what you’re seeing. On the other hand, once you get it warm, it takes a long time to cool off, so you get the benefit as well. You might look at your thermostat location. If it’s not seeing a good average temperature, maybe it could be re-located. The pump was designed for exactly you’re kind of system–relatively large flow rates, and relatively low head loss. I wouldn’t change it, since it wouldn’t have an impact on the problem you’re posing. The curve for the Series 100 Booster is included in the Hydronic Specialties Booster Pump curves–a series of similar pumps all displayed on the same coordinate axes.


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