Is my home's water pressure (90 psi) too high?

October 29, 2008 10:01 AM

Is my home's water pressure (90 psi) too high? 90 year old house with mostly PVC piping. In prep for a replacement hot water heater I measured the water pressure by the washing machine. The pressure gauge showed 90 psi, which seems high. How much of an issue is this?
posted by smelvis to home & garden (6 answers total)

50-100 is normal, enjoy your powerful showers :)
posted by zeoslap at 10:35 AM on October 29, 2008 [1 favorite]

http://www.freedrinkingwater.com/water-education3/8-water-pressure.htm

According to that, it's getting up there.

http://blogs.move.com/behind-the-walls/2007/05/07/water-pressure-regulator-valves/

This recommends a regulator if your water pressure is between 80-150 (or above). Sounds like something you may want to look more into.
posted by Pantengliopoli at 10:37 AM on October 29, 2008

I had water pressure between 100-120 PSI for several years, and it made for louder plumbing, toilets that wouldn't stop (with water bills much higher than they would otherwise be) and faucets that dripped/wore out faster than normal. Because of an ongoing drought in my area I decided earlier this year to become a responsible water user and had a reducing valve put in at the meter; it was about a $300 job but the reduction in my water bill was such that it will pay for itself by the end of the year. My water pressure is now 50-60 PSI, which is pretty standard. Anything above 80 is considered too high.

You might want to leave the pressure guage connected for a couple of days to see if your 90 PSI is at the high or low end of the fluctuations that probably occur in your pressure.
posted by TedW at 10:39 AM on October 29, 2008

You might want to go nuts flushing and see whether the pressure drops...I know some areas of my town that the pressure is a little high because the mains are a little undersized. If this is the case *in*your*house*, the pressure may be making up for deficient water service into the building.

But yeah, we usually install PRVs at 60 or 65 for anything over 80psi coming into the building.
posted by notsnot at 10:47 AM on October 29, 2008

I have a 20+ year old house.

I had random leaks popping up.
One of the sinks in the master bath started to leak.
My dishwasher started filling up when not in use.
Water heater started to leak.
I check my water pressure and it was at 90+.
I lowered it to 40-50 PSI (I have an adjustable reducing valve). Leaks disappeared.

I noticed my shower is not quite as powerful, but it is nothing that bothers me.

Personally, I think if you lower the water pressure you will probably not notice the difference and reduce some stress on your plumbing.
posted by twistedmetal at 10:48 AM on October 29, 2008

Thanks for the info!
Will install regulator with new hot water heater.
posted by smelvis at 11:34 AM on October 29, 2008