Minimax Vacuum Switch Headaches

[sjsoldo]

Minimax 250 NT heater. I know what you are thinking. Get rid of it. But for the most part it still works until recently.

Getting a Vacuum Switch error on the digital display and the ignition module. So I replaced the vacuum switch, error persists.

I took the fan housing apart. Changed the fan ( you can find it on the internet). Put it back together, and sealed the seams with gasket sealant. The connector for the hose on the fan housing was not clogged. I even put some of sealant around the fitting. Error still persists !!!

Now, when I turn on the unit, and take the hose off the connector on the housing, and suck on it (gross), the ignition sequence starts and the unit ignites properly.

What could be the problem?

1. The hose seems okay. As above, suction triggers the vacuum switch.
2. The motor/ fan seems to work properly. Exhaust blows out like it always has.
3. Bad vacuum switch? Seems unlikely that a new one would not work properly.

Very frustrating. Any suggestions would be appreciated.

 

[swamprat69]

If you sucked too hard on the vacuum switch hose you may have damaged the vacuum switch diaphrram. Another problem could be that the heat exchanger is restricted from dirt, leaves or soot. It would be helpful if you had a digital manometer so that you could check the acual pressure in Inches of water column (WC) against the setting of the air pressure switch. If you can't find the setting listed on the switch, check the color on the switch label against this guide Search results for: 'pentair air pressure switch'

 

[sjsoldo]

I think I figured it out. I purchased the wrong Vacuum switch. I got "Violet" which has a setting of 1.35

Should have purchased "Green" which has a setting of .65

I will follow up with the results...