N8N wrote:
On Thursday, July 31, 2014 4:56:00 PM UTC-4, Retired wrote:
On 7/31/14, 4:47 PM, N8N wrote:

Hi all,



Friend's house, complaint is that it is literally impossible to use more than one appliance or faucet at any time due to low water pressure. Asked me if I had any ideas, I said I'd look at it. Finally dug out a pressure gauge and stopped by with it. What I found was that the resting pressure is 90 PSI at the base of the water heater tank, but it drops to about 20 PSI when the clothes washer is filling and it fills very slowly. This seems to indicate to me that there is a massive restriction somewhere upstream of the water heater. My best guess is that it is actually between the street and the house, but that is just a guess as I cannot visually inspect all of the water lines between the main shutoff and the water heater (it's not near an outside wall) nor do I have any idea in what condition they are inside. Just to include as much info as possible, I suspect the house was built in the late 60's or early 70's and all the visible plumbing is copper. I see no evidence of a
pres

sure reducing valve or backflow preventer anywhere.



Is there anything that I can do to confirm/deny my suspicions, or is it time to simply "let the pros handle it"?



thanks



nate





No mention of the main "whole house" shutoff valve. Did you find it ?

Is it fully open ??

Wow.

Normally, I'd respond with a snide comment BUT... I think you may have got it!

I'm posting from that house as I'm still there helping out with some other stuff.

I'd previously located the main shutoff - big (1"? Larger than 3/4" anyway) ball valve in the coat closet behind a nasty unclosed hole in the drywall. Your comment made me go look there again, and down by the floor there was a wooden access panel. So I removed that and behind there was ANOTHER valve, an old stop valve this time.

It was barely cracked open...

one of her roommates was doing laundry so when I heard the washer start to fill I ran over to the water heater and my gauge was showing about 84 PSI.

Flushing an upstairs toilet, turning on the faucet, and turning on the shower simultaneously seemed to indicate that that was the issue. Maybe someone had shut that valve in a misguided attempt to use it as a PRV as the pressure is really rather high?

I will advise that they get new washer hoses and possibly think long term about installing a PRV as 90ish does seem to border on scary. My old place was 80 PSI and that made for badass showers, but I knew full well that on 70 year old piping it was a crapshoot not installing a PRV. However, as it is a three story house, the high pressure may be appreciated...

Sometimes fixes really are easy? I'm on a roll here

nate

Hi,
You mean they always had pressure problem or it started some time ago.
If latter, surely some one touched the valve......