Modine Heater Blocked vent safety switch tripping..
#1
01-14-16, 04:59 AM
Modine Heater Blocked vent safety switch tripping..
Hello all hopefully someone could help me identify the problem with my heater that turns off after 10 minutes.. I thoroughly cleaned the burners and the heat exchanger because i noticed a significant amount of soot. I also found that the last repairman must have cut off the safety switch and bypassed it but i wired it back correctly.. I checked the exhaust and cleaned also just in case.. Once cleaned i turned it on and fires nicely but after 10 minutes the blocked vent safety switch trips and turns the unit off. If you have any thoughts please let me know...
#3
01-14-16, 10:06 AM
Group Moderator
There may be a gas pressure or pressure regulator issue.
Is the heater being run on the intended fuel ? Had it been converted ?
Is the heater being run on the intended fuel ? Had it been converted ?
#4
01-14-16, 11:34 AM
Modine Heater with blocked vent safety switch tripping
Thanks this is a Modine PD50AA0111 Natural gas unit heater and it was never converted.. I get it running for maybe 15 minutes but then it shuts off.. Thanks again for any help
#5
01-14-16, 12:33 PM
Banned. Rule And/Or Policy Violation
Modine Service Parts Locator
The blocked vent switch is described as a part, but not illustrated in the above link.
I would suppose that this is a manual reset snap disc limit switch, is that right?
>
Where there is soot, there is a huge amount of carbon monoxide. A common reason for producing soot is that too much gas is being burned.
A furnace designed for natural gas but which is burning propane would be grossly overfired and producing large amounts of carbon monoxide.
I would leave this turned off until you have a competent person inspect and repair the unit as needed. Frankly, after it's been repeatedly tampered with as you describe, it would be better to junk it and start with something that is a know quantity. Lots of different things could be damaged by overfiring, such as the heat exchangers.
The blocked vent switch is described as a part, but not illustrated in the above link.
I would suppose that this is a manual reset snap disc limit switch, is that right?
>
Where there is soot, there is a huge amount of carbon monoxide. A common reason for producing soot is that too much gas is being burned.
A furnace designed for natural gas but which is burning propane would be grossly overfired and producing large amounts of carbon monoxide.
I would leave this turned off until you have a competent person inspect and repair the unit as needed. Frankly, after it's been repeatedly tampered with as you describe, it would be better to junk it and start with something that is a know quantity. Lots of different things could be damaged by overfiring, such as the heat exchangers.
#6
01-14-16, 01:21 PM
Modine Heater with blocked vent safety switch tripping
Thanks and yes it is a manual reset switch. This was never used with propane. I did find alot of soot in the unit and in the heat exchanger.
I removed the elbow of the exhaust and i noticed alot of cold air rushing in through the vent and when i checked the top of the vent outside there is no cap so i was thinking that the air rushing in was not allowing the heat exhaust fumes to leave easily.. Could that be the problem?
I removed the elbow of the exhaust and i noticed alot of cold air rushing in through the vent and when i checked the top of the vent outside there is no cap so i was thinking that the air rushing in was not allowing the heat exhaust fumes to leave easily.. Could that be the problem?
#7
01-15-16, 03:58 PM
Banned. Rule And/Or Policy Violation
Propane has a much higher BTU input per cubic foot when burned than natural gas. So to meet the specified BTUF input of a furnace, a furnace set up to burn propane would have smaller sized burner orifices than a furnance set up to burn natural gas.
If you take a furnace designed to burn natural gas and burn propane, the too large burner orfices will grossly overfire the furnace, causing soot, massive amounts of carbon monoxide and perhaps burning out the heat exchangers.
If you take a furnace designed to burn natural gas and burn propane, the too large burner orfices will grossly overfire the furnace, causing soot, massive amounts of carbon monoxide and perhaps burning out the heat exchangers.
