Mr heater MHU45NG stopped working

[blairtruck]

i have had this furnace for over 6 years now, in aug 2008 when i joined, and it hasn't failed me once in the northern canadian winters until this past month.
when thermostat calls for heat the furnace LED switches from slow flash to fast flash like it says it should. sometimes the furnace fan clicks but doesn't do anything. and then the flashing led just slowly faded away like it has no power. and nothing ever happens.



i have changed the thermostat and same problem. sometimes if i turn off the power switch to the furnace overnight or for a few hours it will work again for a few startups and then repeat the no working.
i have the side panel off and sometimes when the furnace tries to click on i can see a spark/flame coming from the circuit board.

 

[JackDiddly]

It sounds like you may have a bad ground between the control board and the unit. You should only see a spark between the electrodes that ignite the flame not at the board. I would verify your connections are tight and make sure you have a good ground especially sense it is an intermittent problem and you have been able to get it to work properly.

 

[blairtruck]

ill have a look right away and tighten all wires. -4f outside today. garage is a little cold with no heat.

 

[blairtruck]

haven't figured out the problem. i just unplugged everything from the circuit board and re plugged it back in. check all my connections on the black and white connections.

it turns on but the led sometimes is visible and some time not. i contacted the Mr. heater support on sunday but obviosuly no answer till today. answer i got from them was to supply my address and they will ship out a new circuit board right away covered under warranty even thou i have had this unit since 2008.

 

[toyotadriver]

Glad I have the Mr. Heater. Sounds like great customer service!

Let us know if that fixes the problem.