Can I permanently bypass the vacuum switch?


Old 04-08-19, 03:08 PM
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Can I permanently bypass the vacuum switch?

So I have a ruud power vent water heater and the blower was just running and running but not triggering the vacuum switch. So I swapped out the switch...same problem. Now I think I need a new blower since the vacuum isn't strong enough on the existing one.

Well in the meantime, I closed the circuit of the switch by connecting the two wires that feed the switch so wifey can take a hot shower. Of course the heater fires right up and I just watch it and see that it shuts off on it's own too. So now I'm wondering what the vacuum switch is even for.

Can I permanently bypass the vacuum switch?
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Old 04-08-19, 03:41 PM
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Welcome to the forums.

NO.... you cannot bypass the pressure switch and the unit is setup to not allow that anyway. You need to find the problem. Pressure switches are 99.99% reliable. If it isn't closing..... there is a reason for it. Typically the fitting at the blower end gets gummed up and sealed. Take the rubber line off and make sure its clear as well as the fitting into the blower.

\Have you actually confirmed the vent line is clear ?
Old 04-08-19, 05:23 PM
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The switch you are dealing with actuates with adequate vacuum.
It would be better called by its function which is an airflow proving switch.
That should make it obvious that you certainly need it.
Old 04-09-19, 04:45 AM
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I usually see those switches fail due to contamination like PJmax mentioned. Sometimes the nipple at the end of the tubing clogs. Sometimes the tubing can collect a slug of water, worse when the water turns to snot. And really bad is when the contamination gets up into the switch at which point is better to just replace the switch. Luckily they are relatively inexpensive.
Old 04-10-19, 06:38 AM
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Are the air vents under the water heater clogged to impede the combustion air flow?

Is the butner flame yellow (too little oxygen)?
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