Help for a Circulator Hot Water Heating System

MarkReynolds1

Hello;
I am trying to remotely help my widowed sister in New Jersey get her hot water heating system working correctly, and am running into strange issues (plus some knucklehead techs).
Last winter my late brother in law started the boiler, and it was without issue for the entire heating season. This year my sister has been unable to get it working without almost daily attention.
It is a hot water boiler with convectors from the 1940's. The boiler is from 1983, a 114K BTU Burnham. Photos of the system are attached (the yellow flex connector is for an unrelated appliance).
After a second contractor replaced the gague, pressure reducing valve, relief valve and part of the circulator plus bleeding the convectors, she now has heat. However, if the pressure valve - supply valve is left open, the system will increase pressure to 30 - 35 PSI, and the relief valve will leak.
Close the pressure supply valves and the system will heat at about 20 PSI for the day. In the morning , my sister will find the pressure down to 5 - 10 PSI. Adding water brings it back to the normal pressure and it is good for the day. The daily attention is concerning and my sister is tied to the house, plus the basement entrance is from outside. To my mind this sounds like there is a slow leak in the system, but we can't find any evidence of it.
Any suggestions? The curent Repair man is an improvement over the tech from PSEG (service contract) who claimed "the heat exchanger is leaking carbon monoxide" and claimed she needed a new boiler immediately. Second tech made the repairs but has no other ideas.
I am visiting from Detroit about monthly and can help but this one is baffling. I have Dan's "Classic Hydronics" book but don't fully understand everything yet, this is much more complicated than steam.
Help is appreciated, Thanks.
Mark Reynolds
Mark

hot_rod

Sure feels like a leak somewhere. Will pressure drop to 0 if left overnight?

Should really have a backflow preventer on the fill.

Interesting oiler on the circulator😁

EdTheHeaterMan

The auto feed looks new. I wonder if it is adjusted properly or if there is some debris in the valve that is preventing it from shutting off completely at 12 PSI. My first task would be to check the adjustment on the auto feed and make sure it is set to 12 PSI.
1. Open and close the fast fill lever several times to clear any debris from the valve.
2. Then adjust the pressure setting. That is done with the top screw. The nut on top locks the setting once you get it where you want it. A 7/16" box wrench will loosen the lock nut, then back the screw adjustment out (turn counterclockwise) until you hear the water stop flowing in the the boiler.
3. Leave the manual valve open to see if the pressure stays at 12 to 19 PSI over a boiler cycle. The pressure will go up when the boiler is hot and go back down when the water cools off.

kcopp

Looking at the vent pipe from the boiler... it has a good amount of corrosion at the joints. To me that makes me wonder if there is a small leak on the heat exchanger. Pull that off the top of the boiler. What do you see?

mattmia2

If it has had a lot of fresh water added then it could just be the air that was in that water working its way out. If you top it off for a couple days(but leave the supply closed unless you are adding water), do the hot and cold pressures stabilize?

mattmia2

The vent needs some attention, it is corroding, the vent form the water heater is going down hill, it is possibly getting spill from the water heater corroding it, but in any case 1 you need to have a low level CO monitor and 2 need to find someone that is good with combustion analysis to figure out the venting.

hot_rod

kcopp said:

Looking at the vent pipe from the boiler... it has a good amount of corrosion at the joints. To me that makes me wonder if there is a small leak on the heat exchanger. Pull that off the top of the boiler. What do you see?

Possibly the WH vent running downhill?