Plumbing question/issue

[dave1949]

My understanding is you should have an expansion tank on your water heater if you are on a city water supply. If on a well, the air bladder in the pressure tank serves that purpose.

We just had a 55 gal. Marathon elec. water heater installed in August, it replaced an in-direct fired tank (zone off our boiler) and it had an expansion tank. The installer asked me why the expansion tank was there. I said I have no idea, so he explained why it wasn't needed since we are on a well with pressure tank and air bladder. So, we don't have an expansion tank anymore and have had no issues.

 

[deerefan]

I would start by checking the water pressure while the problem is happening, to see if there is a change in the pressure. Sounds like there may be a restriction somewhere in the water system. Does it do it when the cold or the hot water is used or both? This could narrow it down to the cold or hot system. Have you checked the valve on the heater to make sure it is all the way open? It sounds far fetched, but I have seen valve that will close themselves over time. I have been a plumber for almost 40 years, so we should be able to figure this out.

It only happens when hot water is used. I do not have a shutoff valve on the hot or cold supply side, only at the water meter 600ft away at the road.

 

[hosspuller]

I have a theory... The pressure is caused by the water in the heater expanding. Ordinarily the expansion is absorbed by a tank or backflow out of the heater. There might be a valve that is blocking the flow out of the heater. (Such as antisiphon valve)

one way to check is immediately after a shower, open a hot water valve to a trickle to bleed pressure. If the problem goes away, the heater is building the pressure. Then you can check the expansion tank for the heater for function.

 

[deerefan]

I would start by checking the water pressure while the problem is happening, to see if there is a change in the pressure. Sounds like there may be a restriction somewhere in the water system. Does it do it when the cold or the hot water is used or both? This could narrow it down to the cold or hot system. Have you checked the valve on the heater to make sure it is all the way open? It sounds far fetched, but I have seen valve that will close themselves over time. I have been a plumber for almost 40 years, so we should be able to figure this out.

It only happens when hot water is used. I do not have a shutoff valve on the hot or cold supply side, only at the water meter 600ft away at the road.

 

[deerefan]

It only happens when hot water is used. I do not have a shutoff valve on the hot or cold supply side, only at the water meter 600ft away at the road.

Sorry for the duplicate posts. Iphone acting up.

 

[boggen]

there would need to be a lot of "IF's" for it to happen, but main suspect would be "air" is getting into your system. and very well could be coming from the rural water company, and there is a chance your local nearby neighbors may not have problems. your near by neighbors may be low side or high side in how the plumbing out side runs under ground. and you just happen to live in the right spot were air builds up in the water line outside along the road, and allowing air to go into the pipe that feeds your house.

if you had a private well, cavitation from the well pump, might be issue. but being this is a rural water company that feeds you....

i have a hard time believing air coming from a bladder tank, or pressure tank. if the problem is day in day out. after a few days the air would have depleted from a pressure tank, i would like to believe, or less you were hooking up air compressor to the bladder tank / pressure tank every couple days.

i might buy into, your shower, is allowing air back into the system. Example. i have a private well, and when doing water change on fish pond down stairs. i open up one 1" ball valve and one 3/4" faucets, so i can quickly deplete the pressure tank, and then simply rely on just the well pump, to push water into the fish pond. this lowers the PSI from 30 to 40 PSI down to only a couple PSI. i can hear air "bubbling" back into the pipes, when i have both faucets on. doing this, after i am done filling the fish pond back up. any faucet up stairs, or toilet flush, will get a few "gasps" of air coming out of them. and in a rare case every now and then, i might hear a pipe rattle some, as air shoots past a spot, going to another faucet.

=====================
what type of pipes and/or hoses do you have in your plumbing? metal? like copper? or PVC / CPVC plastic pipe? or PEX hose like pipe?

and how old is the plumbing in the house?

 

[plykins]

It only happens when hot water is used. I do not have a shutoff valve on the hot or cold supply side, only at the water meter 600ft away at the road.

I am leaning toward the build up of pressure from the heating of the water in the heater. Has your water meter been replaced recently? Most of the new meters have a built-in check valve to prevent backflow into into the public system. This causes a closed loop in your water system. Meaning any expansion in the system has no where to go. This is why many cities are requiring an expansion tank at the water heater on the cold side. This may be your problem and solution. As was stated earlier the next time you use the shower, turn on the hot water at one of the sinks to a slow drip(relieving the build up of pressure). After a half hour or so, see if the problem has disappeared(by turning on another hot water outlet and seeing if the sound is gone).

 

[deerefan]

I am leaning toward the build up of pressure from the heating of the water in the heater. Has your water meter been replaced recently? Most of the new meters have a built-in check valve to prevent backflow into into the public system. This causes a closed loop in your water system. Meaning any expansion in the system has no where to go. This is why many cities are requiring an expansion tank at the water heater on the cold side. This may be your problem and solution. As was stated earlier the next time you use the shower, turn on the hot water at one of the sinks to a slow drip(relieving the build up of pressure). After a half hour or so, see if the problem has disappeared(by turning on another hot water outlet and seeing if the sound is gone).

Just did as you suggested when I took my shower. The issue did not happen. Thoughts?

 

[plykins]

Just did as you suggested when I took my shower. The issue did not happen. Thoughts?

Sounds like you need to install an expansion tank at your water heater. You can get them at Lowe's or Home Depot. Install a tee fitting as close to the cold water inlet on the water as you can. Insuring that there is no valve or check valve between it and the heater. This may be a good time to install you a valve on your water heater.(so when there is a problem with the hot water system, you can cut off the hot water at the heater and not 600 feet away at the meter.) There are lots of how-to's on the web for this. According to your information a 2 gallon tank should work fine.

 

[deerefan]

Sounds like you need to install an expansion tank at your water heater. You can get them at Lowe's or Home Depot. Install a tee fitting as close to the cold water inlet on the water as you can. Insuring that there is no valve or check valve between it and the heater. This may be a good time to install you a valve on your water heater.(so when there is a problem with the hot water system, you can cut off the hot water at the heater and not 600 feet away at the meter.) There are lots of how-to's on the web for this. According to your information a 2 gallon tank should work fine.

I will grab one up while I am out tomorrow and install this weekend. I will update findings once done.