Water Heater Pressure Switch Mystery

Just a guess. The coupling with the two clamps is not sitting square on top of the blower. It could be leaking and affecting the exhaust pressure.

Maybe the blower is failing and not developing sufficient d/p??

Hmm, good thinking, Im going to call a tech.

Being that this is a DIY forum I'd suggest you get a digital manometer like the one below. No idea if this particular one is any good but you get the idea. Check the differential pressure that the switch is seeing and compare to the spec which should tell you if it is the switch or maybe the blower (assuming no blockages). Even if it doesn't give you a definitive answer you'd maybe have more confidence in what a tech tells you.

Also, I don't know about your water heater but furnaces often have flexible tubes that connect up to the pressure switches on inducer fans and those can get clogged and cause this kind of fail. Usually easy and quick to blow them out. Take a look at yours and see if that might be a problem.

https://www.amazon.com/dp/B07CWQJD6...jdCZkb05vdExvZ0NsaWNrPXRydWU=#customerReviews

djlandkpl said:

Just a guess. The coupling with the two clamps is not sitting square on top of the blower. It could be leaking and affecting the exhaust pressure.

Click to expand...

Turned out that the couplings were very loose :sad:

Thanks for all the advice everyone!