ML193UH070XP36B-3, heat stays running after thermostats satisfied. Flame not just blower. Both thermostats changed. Stats running even if thermostats removed from back plate. If unit is shut down and the restarted does not ignite until thermostat calls but then stays running. Have checked wiring and everything goes where it is supposed to on thermostats and control board on furnace. Looking for troubleshooting tips. Would limit switch cause this ? hoping not control board
Take a look at the diagnostic LED's on the control board. Under normal conditions with no call for heat, they should both be flashing slowly. When furnace is calling for heat, they should both be flashing faster. If they are both flashing fast when you think the call for heat has been satisfied, the furnace thinks there is still a call for heat.
That could be a thermostat wiring issue or a control board issue.
If they return to flashing slower when the call for heat is satisfied but the burner and blower continue running, that is likely a control board problem.
I couldn't find a schematic for that board, but it looks like there are several relays on it. A few light taps on the relays when it is "stuck" may show up a sticking relay.
Remember that the blower will continue to run for a while after the burner shuts down.
Yes, 2 thermostats, thiu 2 zones. Zoning control Honeywell HZ311. This is at 2nd home so not at it till weekend.
Houston could you LMK what would determine bad board? ie remove W wire at board and flame stays on means ? or remove W wire at board and flame goes out means ?
I have purchased board and would like to diagnose and install if necessary this weekend. Not great wifi to check in here, when there so trying to get as much info upfront. really appreciate all the help !
Either thermostat will activate the HZ311 and the HEAT LED will come on.
You'll want to make sure the HEAT light is out.
If it stays lit.... the HZ311 could be the problem.
Hello! I just had my gas valve replaced on our burner. It's a honeywell/Resideo vr8300A3518 and was a direct replacement. It was installed by the people I usually have do any hvac/plumbing work on my house.
The problem is that once it was installed, the technician told me the pilot light was high and that he wasn't able to adjust it. He said it is OK but just using a bit more gas for the higher pilot light. No big deal.
I went to look at it a day or two later and it is pretty high! About an inch tall. I also tried the adjustment screw and it doesn't matter which way I turn it, it doesn't move. Any idea what would cause this? Are the adjustment screws replaceable at all? The valve works fine so I don't want to replace the entire thing again.
As a side note, I purchased the part (new) myself and matched up part numbers. The tech did double check everything was correct and was OK using the part. I don't normally do that but I was going to change it myself before realizing there was pressure limits and I didn't have the right gauges and tools to check them.
Hi all,
I bought a home heating oil tank in line fuel filter. Im tired of changing my nozzle once or twice a winter and cleaning my small pump filter then have to prime. Cant be good to have to keep taking it apart.
Anyway, I have my tank out back, its a trailer.the supply line is small copper line in the dirt to the house. Maybe 20 feet lin length. I'd like to install a filter right off the hardline right after the tank shutoff valve. I dont have welding skills but I've changed transmission and radiator hoses etc.
can I use flexible hoses with clamps to install the filter.
I dont see a problem with it minus insurance qualms or maybe state law or codes requiring hard line. I dont have much clearance from the supply line to the ground if any so this would also facilitate that issue rather then having to figure how to raise that line or dig a hole for a box to hold filter. I dunno. I figure if I secure everything tightly it will be fine and put it in an aerated box above ground.
So in your answer other than law or insurance issues, is there mechanical issues if I use fuel rated hoses? Short hardlines from inlet and outlet to the hoses since those are female and to make a males connector for the hose.
thank you