hydronic baseboard heat not keeping up


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Old 02-13-11, 10:07 AM
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hydronic baseboard heat not keeping up

I'm new to this site. I've got a hydronic baseboard heating system in my house . the guy who built the house in 1978 was a plumbing contractor. this season my system isn't keeping up. i tried bleeding my baseboards and found that a few of them were hot but no water came out of fittings, i heard air but no water and one fitting was cool. do i have a clog? and if i do is there anything i can do?
 
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Old 02-13-11, 10:57 AM
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Do all your radiators get hot? What is the pressure in your system and what is the temperature?
 
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Old 02-13-11, 11:00 AM
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What droo said about the pressure... find the gauge on your boiler and tell us BOTH temperature and pressure.

It sounds like you don't have enough pressure in the system.
 
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Old 02-13-11, 03:34 PM
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thanks guy's the t-stat isn't calling for heat today ,but when it does the water gets to about 189. the water pres. is at just over 5 psi ( gauge has 5 psi increments) the system is gurgeling alot though.
 
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Old 02-13-11, 04:24 PM
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Sounds like a pressure problem. You need to bring more water into the system until you have 12-15 psi when the boiler is cool (100F). It really should fill itself automatically. There may be a valve that is shut that is preventing the make up water to enter the system or there could be something wrong with your auto fill valve.
 
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Old 02-13-11, 10:07 PM
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it has an auto fill/backflow preventer and an expatsion chamber. but you know we had the water main break in three different places last week on the other side of the road, and i think we got a bunch of air in the system could that be causing the problem?
 
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Old 02-14-11, 04:52 AM
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Air definitely can cause a problem but your problem is two fold. You have low pressure as Droo stated, you need to have enough pressure to fill the system to the high point. The other side of this is the pipes are not full of water so you lose btu output. Water et the bottom of the pipe will heat the whole pipe but not as hot as if it were full of water.
Any air in the system even if the pipes were full of water but still had some air we reduce the heat output and slow the flow. When we have air in the system we reduce circulator head pressure we reduce flow. When flow is reduced we reduce the heat output.
 
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Old 02-14-11, 05:23 AM
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The water main break would not put air in your system. It is the fresh water that does that. That break may have put a large amount of sediment into your water and I wonder if that sediment has caused a problem at your auto fill valve.

Use the fast fill lever on the auto fill valve to get water into your system and your pressure up. If there any problems with your hardware, they should become visible once you get your system up to pressure.
 
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Old 02-14-11, 06:00 AM
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The water main break would not put air in your system
Wouldn't think so either, but it's possible ... depends on how low the pressure went on the domestic supply to the home, and whether or not the backflow preventer or check valve in the pressure reducing valve is functioning properly.

This is EXACTLY the reason for the backflow preventer on boiler systems.
 
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Old 02-14-11, 06:15 PM
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i'm not sure if i have a quick fill valve. after the backflow preventer i have a ball valve ,then a pressure regulator ( by the way my pressure has dorpped to 0 ) after that the line runs to a air release valve and the fitting for the sonitrol expansion chamber , i'm not seeing a valve after that?
 
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Old 02-14-11, 06:21 PM
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as for the air in my system ,for some reason when they shut off the water to our street it drained my hotwater heater (house) and the tank to my hot water maker . because when they turned the water back on i had cold water right away but i had to bleed the air out of the lines on the hot side for like three to five min. before i got water.
 
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Old 02-14-11, 06:48 PM
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You also need a main water meater with a built in check valve as a back up.
 
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Old 02-14-11, 06:55 PM
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because when they turned the water back on i had cold water right away but i had to bleed the air out of the lines on the hot side for like three to five min. before i got water.
And did they have you on a 'boil order' ? If not, they certainly SHOULD have! Think about all those nasty little buggers that could have crawled outta that muddy hole and into your domestic water supply.

then a pressure regulator
Another name for your 'pressure regulator' is 'auto fill', 'pressure reducing valve', and others. There should be a lever on that pressure regulator. That lever will be your 'quick fill' ... what make/model is the pressure reducing valve?
 
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Old 02-14-11, 07:01 PM
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( by the way my pressure has dorpped to 0 )
This is not a good sign. Your heating system should be 'pressure tight'. There should be no reason other than a leak somewhere for the pressure to continue to drop. Well, other than the boiler cooling off. THIS is the reason that every time you mention a pressure, you need to tell us what TEMPERATURE that pressure reading is taken at.

If the ball valve on your water feed line to the boiler is open, and you have no pressure in the boiler, it means that the system isn't being fed any water.

While the system pressure is at zero, put an ACCURATE tire pressure gauge on the air valve on the expansion tank. If it is less than 12-15 PSI, add air with a small compressor until you have 12-15 PSI in the tank, and the BOILER STILL AT ZERO. If ANY water comes out of the air valve on the tank, replace the tank, it's shot.
 
 

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