BASIC Water Pressure Valve Q

[Ydhtbiotsao]

After I installed a new water heater in our basement, I inserted two pressure gauges on both sides of the water pressure valve. The first gauge (herein referred to as gauge1) remained pretty constant showing 80 psi coming in from the city. The second gauge (herein referred to as gauge2) would vary from about 45 on up to 80. Most of the time it was 45 when I checked it. That lasted about 7 months. Then came some weird noises - like cats or maybe parrots imitating cats, but short of what I'd call water hammer, or maybe parrots imitating water hammer. We do not have any cats or parrots. I went to check the gauges. Both were up to 80. I adjusted the valve counterclockwise several turns and watched the gauges. Neither went down until my wife turned on the water upstairs. Then gauge1 stayed at 80 and gauge2 went to ZERO. My wife said the water started coming out fast and then slowed to a trickle. While the faucet was still open, I turned the valve clockwise. As I turned the valve clockwise, water started running again and gauge2 went up to 30 while gauge1 stayed at 80. Next she turned the faucet off and gauge2 increased to 50.
I think I said all this right. But, BUT, if I wait a long time, for some reason gauge2 is up to 80!

Q: Would that 80 after a long time indicate a slow leak in the valve? Wouldn't 80 be too much pressure on the water heater?
Otherwise, does all this sound right? Is this how it's supposed to work? Seems to make sense, but not sure.

 

[WorthFlorida]

Water heaters have heat traps inside the nipples right at the water heater. They act like a check valve. Water may not back flow from hot to cold every time. These heat traps are nothing but a ball. Google heat traps for water heaters. Occasionally this balls can get hung up.

If you're worried about pressure, an expansion is needed. It's mandatory in some areas and the manufacturers are requiring it in the installation instructions.

 

[Sponsor]

 

[Reach4]

1. When adjusting a PRV, do it with water trickling somewhere in the house.

2. 130 PSI would not damage a WH, so neither would 80.

3. Sounds from the PRV tell me that the PRV should be replaced or rebuilt. If there is a slow leak, that is another indication.

4. Some PRVs have a "bypass" feature, and will pass water toward the meter if the pressure in the house rises much above the incoming water pressure. Depending on if there is a check valve at/in the meter, that might eliminate the need for a thermal expansion tank-- until they come along some day and add a check valve.

 

[WorthFlorida]

When water is heated in a closed system, pressure will increase.

 

[John Gayewski]

Do you have an expansion tank? Hot water expands into a pressure reducing valve which is a one way valve. This will increase the pressure on your system. If you have a prv you have a closed system which requires an expansion tank.

Your homes water pressure should no get up to 80. Call a water heater company and try to have them warranty your water heater while telling them your homes water pressure exceeds 80 psi. They tell you to kick rocks.

 

[WorthFlorida]

".........check the gauges. Both were up to 80. I adjusted the valve counterclockwise several turns and watched the gauges. Neither went down until my wife turned on the water upstairs. Then gauge1 stayed at 80 and gauge2 went to ZERO.

You seem to have two pressure reducing valves with added gauges. Only one PRV should be used, not two. The PRV is usually at the service entrance for the home on the cold water side, not after a water heater. Two PRV's can be used right next to one another.

Water fixtures for homes are usually rated at 150 psi max.

 

[John Gayewski]

Rated at and operate at are different things. Since pex is tested with 210 degree water does that mean we should start heating our water to 210? Cpvc also has a rated intermittent use at 210. So that's telling me our house water is way too cold.

 

[Eman85]

I'm not a plumber. When my PRV went bad it made noise and also the water pressure would fluctuate, you could tell when showering as it fluctuated. If you think the pressure is rising because of the water heater shut the water heater off and see what happens.