Massed615

I just bought a house and the bank I bought it from hired a plumber to install a boiler. I had some say in the matter but was ultimately advised to go with a Laars Endurance due to some direct venting issues. I had no problems with the boiler until it started getting cold out (below45). Once that started happening I noticed the base board wasn't putting out much heat, I can set the thermostat to 90 degrees and the room one get above 54 on a bad day and 63 on a good day. There has been an occasion or two when the temperature has reached 68-70 so the system is capable of heating the area its just most of the time it doesn't. I called the company that installed it(who I don't trust farther than I can throw them) and they told me that the pex feeding the base board was too small, ½ opposed to 3/4, and that I needed more base board. But I was told that Half inch pex has the same flow as 3/4 copper because there are no fittings and like I said the system can Heat the whole area at times so I don't think I need more baseboard. I have a digital thermostat and which I have programed and reset and reprogrammed to make sure that wasn't the issue. My next thought ist to bleed the system but I'm not quite sure how to do that. Any suggestions? sorry the post is so long

JohnH1

Man were to start. I could be sooo many things. 1st 1/2 pex is not the same as 3/4 copper. Has it heated to normal temp when it was cold out or only when the weather was mild.

Massed615

When it was cold out

JohnH1

Next when it dosent heat enough does the burner cycle off or continue to operate.

Massed615

continues to work as long as the digital thermostat is set above the current temp. My gas bill was$180 last month

JohnH1

If it continues to operate then it is giving up all the heat the boiler is putting out. Check that the boiler is firing at full rate.

Massed615

You'll have to bare with me I have no HVAC experience what soever. What I do know is that the digital read out for the tank temp 190 degrees and my hot water works extremely well

JohnH1

Hopfully the 190 is the boiler water temp and not the domestic water. If you are delivering 190 deg water to the heating system and the burner dosent shut off then it sounds as if the boiler is to small except for the fact you say it has heated durring the same cold weather otherwise. Maby others can think of somethin els.

Massed615

no my domestic is set around 140-150, i have no small children and i think my wife is smart enough not to put her hand in scalding hot water

Massed615

Please excuse my mis use of terminology but I read some where that the heat exchange can get clogged with air?

JohnH1

Nah if is was air bound it would be cycling on high limit. Are you sure the burner (fire not pump) continues to run when the house is cold and not able to keep up.

Massed615

The burner only runs when the tank temp drops to 150-160 then it fires it up to 190 and shuts off

JohnH1

Ok so the burner does cycle off when the house dosent maintain temp. This says it is not the boiler itself. what type of heat emitters are in the house. Copper tube baseboard?

Massed615

copper fin baseboard fed by pex on the first floor the second floor is a heat pump fed by pex and that work great

buletbob

dont want to but heads on this post, but I would say the system was choked by the 1/2 Pex. going from 3/4" to 1/2" on the first floor I would have to say your choking the zone. BOB.