North Metro HVAC recommendations?

Most likely going to need to get someone to the house, looking for advice.

Garage heater quit working. Hamilton model WGH45AH0134. Burners would light as normal, but the blower fan wouldn’t kick in. LED code said Limit Control or Flame Rollout Switch. Tried to push resets on Rollouts, no click, and now getting different code. 3 flashes – pressure switch and the burner will not light.

Could all or any of these be the issue or is it possibly the board is bad and throwing false codes?

Thanks,
Dean Thorn

When you say blower, do you mean main blower or combustion air blower??

Don’t have a manual on this one, sorry..not much help.

Al

The main blower, I guess. The fan on the back of the heater that blows the air over the tubes and out to the garage.

power it down, remove the flame sensor and clean it with steel wool, put it back together and power it up and see if it stays. Usually if they trip out a few times they go into a different alarm state and need to be powered down for a bit.

Thanks, will try cleaning the flame sensor. I flipped the breaker (dedicated circuit) last night and tried it again this morning, that is when the burner wouldn’t light and the code for the pressure switch started. Last night the burners worked, just no fan blowing the air, reuslting in the burners cycling on/off.

Normally if the main blower won’t come on you’ll get a high limit tripping, not the rollout.

If it has a pressure switch, does it also have a combustion air motor and is that going?
They usually start up before the burner comes on.

Pressure switch fault code could also be vent is blocked.

Al

Allen,
The combustion blower was working last night, but not this morning when I tried it. Not sure how the vent could get blocked, but anything is possible. It is a horizontal vent out the side of the garage, with a cap on the outside.

The limit switch was my first thought, tried unhooking the wires (one at a time as not to switch them) and hooking back up in case they were loose. After I did that, the burners won’t light and I get the pressure switch code.

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Allen,
The combustion blower was working last night, but not this morning when I tried it. Not sure how the vent could get blocked, but anything is possible. It is a horizontal vent out the side of the garage, with a cap on the outside.

The limit switch was my first thought, tried unhooking the wires (one at a time as not to switch them) and hooking back up in case they were loose. After I did that, the burners won’t light and I get the pressure switch code.

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Blocked vent was just one of the things a pressure switch fault code can mean, also a combustion air motor not running can give the same code.

Limits are just usually a on/off kind of switch.

Usually normally closed and open when they reach there set temp.

If you can, see if you have voltage to the combustion air motor when there is a call for heat, if so, maybe bad motor.

Hard to do over the web with out seeing what ya have.

Al

Are they the black round vacuum pressure switches? Atleast twice a year the furnace in my house some how gets moisture in them and causes them not to close. Only happens when I gets real cold out…. When the furnace fires and then goes into alarm I pull the vacuum line off and suck on it a few times then hold and I usually can get it to go out of alarm and fire up then I dont have any issues until the next big cold snap. sounds weird but happens every year. try googling “arnold service trouble shooting” he as a pretty good write up on things to try

Just wanted to say thanks for the help on diagnosing my garage heater problem. It turned out to be the control board. Bought a new one, replaced it, and it is going strong.

Dean Thorn