Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 7/10/2017

when changing a water pressure reduction valve, do you have to turn off the supply to the hot water tank first?

don't want to ruin the hot water tank

Do you have the same question? Follow this Question

1 Answer


The water has to be shut down to the regulator location and to all pipes "downstream" of where the pressure reducing valve is going - so main water shutoff if a whole-house pressure regulator, or sometimes separate shutoff valve just to the appliance being worked on for boilers and water heaters and such - though not all have dedicated cold water shutoffs (though they should for use in case they develop a leak so the entire house does not have to be shut off in that case)..

And if shutting off water (and draining water out of pipes to do the pressure regulator installation), tankless type heaters should have the power/gas turned off to them completely because they can drain/siphon dry and be damaged that way if the power is left on. Regular tank type water heaters are fed from the top, so generally will not siphon the water out when you drain the pipes (though I have seen it in ones with filler dip tubes reaching the bottom of the tank) - but because you are draining at least part of the piping my practice is to turn all tank type water heaters and boilers down to at least pilot only if not compoletely off (or to OFF if no standing pilot) - that way you greatly reduce or eliminate the risk of overheating in case the job takes longer than expected and the water is off for a day or so (say a pipe breaks in the process or such) rather than the expected hour or so. of course, they then need to be turned back on once the watewr is back on AND water has been run through the hot pipes to flush out the air - that is CRITICAL for tankless heaters, because jusat turning the water back on does not necessarily fill them - without a hot faucet open downstream open the water may jusat pressurize the air in the pipes and not fill the heater.

Answered 3 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy