Beacon Morris Heater

[MountNMan56]

I have a nat. gas heater in my shop. Lately, it lights and heats up, but the fan only comes on about 1/2 speed for about 5 seconds then shuts off. Any ideas?

 

[Showkey]

Did you look for trouble codes ( flashing light) on the board ?

 

[D45]

What size is it?
Yes, check for flashing codes on the board

 

[MountNMan56]

I haven't done that. I will do that and get back. Thank you

 

[MountNMan56]

I checked. It flashes 4 times. It say's that the limit or rollout switch maybe open, however, I can't find one on this unit. This is a 150000 BTU unit, Model TF/BTU150

 

[D45]

The sensors should be near the burners

Check and make sure the top burner isn't rolling up and over the top

You might need to do the burner pinch mod, it solved my heaters issues

https://www.garagejournal.com/forum/showthread.php?t=374715

 

[MountNMan56]

There is a sensor there, but it does not have a reset button on it.

 

[Showkey]

You mentioned the fan blower was running half speed????

If that’s the exhaust power vent running slow..........then the roll out sensors would sense an over heat situation.

 

[MountNMan56]

No, the power vent runs fine, it's the main fan that blows the heat.

 

[Showkey]

Slow main fan could also cause an overheat situation tripping the safety sensor.

The tripping has a cause and resetting then detailed testing is critical.

 

[MountNMan56]

The power vent fan runs constantly, the blower fan comes on and runs for about 5 seconds, then shuts off, then, the ignitor clicks and the gas lights and stays on for about 10-15 seconds, then goes out. Then it starts all over again. I watched this today.

 

[Showkey]

^^^^^^^^^^That explanation sounds more like the flame sensor is not being satisfied.

The flame sensor confirms a flame is lite and present. If not satisfied it shuts down the gas valve. Then starts lol over again. Most units give up after 3-5 try’s. The flame sensor generate a few micro amps so they are very sensitive to dirt or corrosion.

Often they are just dirty and cleaning is all that is needed witha dollar bill or scotch Brite pad.