Minimax 400 has flickering lights and clicking

[Bob123]

Hi, I am not sure how to proceed. I have a 15 year old minimax 400 heater. When I turn on the heat, all 4 lights (TSTAT, AUX, PRESS and HEAT) come on and it begins heating. Within a minute, all 4 lights start flickering and I hear a clicking from the control board and the gas valve. The clicking matches the speed of the flickering. After a shot while, the heat light goes off and the others stay on, still flickering. Now the only clicking I hear is from the control board.

I have already replaced the transformer but it didn't help. It was rusty and had an exposed wire so I don't consider it a waste of money.

I'm thinking I need a control board but I don't want to buy one if I don't need it. Any advice would be appreciated.

Thanks

 

[ps0303]

These types of issues are tricky as you are kind of left trying this or that. I would have to agree with you that the next step would be the control board but I would also check the wiring inside first to make sure there are no other bare wires etc.

 

[danpik]

To add to Paul's comments, Remove and clean all wiring connections. Also if it is a spark ignition, the flame sensor circuit may be acting up once the unit heats up. Make sure there is no rust on the flame probe and the area surrounding it. The pilot assembly also needs a good clean connection to the chassis for this circuit to work. last, clean the burner tubes. If they are corroded or clogged up the flame will not stay steady and cause problems.

 

[Bob123]

Thanks for the tips. Today, at one point, the T-STAT light was the only one on and it was flickering rapidly. I should also clarify when I say flickering, I mean like 3 times per second.

It's 105 here today in Texas so next weekend I'll try your suggestions. Thanks again