Sounds like they should purge the air from the system, if the pipes have air in them the water won’t flow through the pipes and the system won’t automatically purge the air out. Is the house two stories? If so you may have to run the boiler water pressure up around 18-20 psi.

I see it was suggested to buy a Infared heat thermometer and I also recommend that option so you can tell if you’re getting circulation, as then you would know what the pipe temp is throughout the whole system.

I think the second guy nailed it being undersized, your area calls for about 50 btu/ sq. ft for baseboard heat. But if you are maintaining 170* water that should be sufficient, is that boiler loop temp or heating loop temp? Pics are blurry when zoomed in to see if the piping layout is correct. What is that unit to the left of the boiler hanging on the wall, piped into the boiler loop, the one valve to it is off. I would hope both techs would've checked for air lock.

901

To me the key to fixing the problem is where OP said heat on each side of fin tube and fin tube is cooler. Airlock IMO.

Wouldn't undersized boiler use more fuel and run a lot more? He said he is using a lot of fuel.

Wouldn't an air lock cause it to use more fuel too. The water is hot but not going any where it thinks its cold. It sounds like it is burning plenty of fuel. I switched over to my second 500 gallon propane tank on the 6th of Jan. I have forced air.

I have limited experience with propane systems except temporary propane unit heaters during really cold and it turning to liquid. It seems that the furnace is computer controlled and it may not be able to figure out that there is a problem so just burning fuel.

Not sure if it is still a problem since OP hasn't commented since last evening.

Yes, agreed and that's what the second service tech diagnosed as well and the problem seemed to surface during sub zero temps. Hard to say for sure without being there but if the entering & leaving pipes are both hot but the fins are cooler, the heat is being transferred to the air flowing across them which is normal. The return temp & boiler cycle times would be telling. If supply & return temps are decent but the boiler is running continuously and the house isn't getting warmer just screams undersized. I ruled out the air lock only because with as many techs were troubleshooting it, surely they'd find that...but you never know

Curious to hear what the problem is. Not all hvac people know there stuff. I built a new house in 2007 and had my nephew who owns the company give me a bid.ive got a outside wood boiler and needed pex hose ran in.underground.told him how I wanted it done,wanted the insulated pex hose for outside boilers.yep I know what you mean he told me.i came home from work one night and he had the trench dug and pex hose laying in it ,but wasn't the type I was talking about so I called him and said this isn't the insulated pex I was talking about.he said we use this all the time,I told him 3 times before they filled the trench in that it wasn't going to work.he assured me it would.went down new years eve to fill the stove and slid on the mound of dirt .called him and told him the ground was thawed where the pex hose was running underground and he better get his butt out here.needless to say I went thru a pile of wood that year.the following summer he came out and dug it up put the insulated pex down like I told him too do.no problem since.

I see pressure/temp gauges on the supply and return. I'm curious what those are reading.

There is a big difference between residential and commercial heating tech's.

Usually the zone valves ( gray boxes with wires coming out above the circulator pump) have a spring loaded lever located under the wires. If the zone valves are open and allowing water to flow through you can move the lever with no resistance, if the lever moves but with resistance then the zone valves aren’t open. I assume they are working. You can also manually lock the zone valves open with the lever by pushing it open and then push it behind the notch in the housing

The gray tank on the floor is the systems expansion tank, it allows the heated water to expand and not cause the pressure to rise. The brass unit on top of it a spiravent and it removes the air from the system as the water flows through it.

If one section of fin tube has an airlock and hot water is passing through but because of air its partial it would effect the whole system. Auto bleeders are notorious for not working.

Maybe the OP has fixed the problem! Would be good to know the outcome and that they are warm!

If you look close at the stainless steel tubing coming out of the boiler the arrow on the manifold points to the right for flow. And the pump is pushing water to the left. They have the pump going the wrong direction.

They didn't change it, they want to till tomorrow.

I don't know what there plan is. There coming back tomorrow morning.

Easy enough to reverse the circulator.

The arrow was hard to see. I was trying to trouble shoot it when I seen the arrow with flow direction. I called the company and the owner came out. He said his guys messed it up. And they will take care of it.

They will push the water into the return lines. How will that work?


I open just about all the bleeder valves on the registers. There was no air.

Too bad you have to wait another day! Easy fix he should have done it.

I am not so sure that is the problem. Years ago I installed my boiler and the pump was running the wrong direction. It worked for many years that way until I had a new boiler installed and that's when I found out. It just was always noisy!

It looks like a pretty clean install. They should have you on your way in a matter of minutes. They isolated the circulator well.