Water heater overflow dripping
#1
02-10-18, 10:44 AM
Water heater overflow dripping
I had to relieve some pressure from my hot water tank to do a plumbing repair (hole in poly piping 
) and now the pressure relief valve will not stop dripping. Will this stop once more pressure builds up? It's been about an hour and it is still dripping about two drops per second. Guess I'll put a piece of hose on the end of the discharge pipe and run it into the sump basin, but I'd obviously like to fix it. The water heater is only 4 or 5 years old, not that that means anything.
) and now the pressure relief valve will not stop dripping. Will this stop once more pressure builds up? It's been about an hour and it is still dripping about two drops per second. Guess I'll put a piece of hose on the end of the discharge pipe and run it into the sump basin, but I'd obviously like to fix it. The water heater is only 4 or 5 years old, not that that means anything.
#2
02-10-18, 11:00 AM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
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First of all, it is NOT an "overflow" it is a safety valve. The pressure in the tank will return to normal instantly when you let the valve close so it is not a lack of pressure problem. What is most likely the problem is a small bit of dirt or other corruption (that's a technical term) keeping the disc from fully seating on the disc.
To flush the valve put a bucket under the drain piping and then pull the handle wide open, let it blow for a second or two and then let the handle snap shut. It is normal for the pipe to drip for a few minutes as all the water drains by gravity but it should stop in five minutes or so. If it still drips then it needs to be replaced.
To flush the valve put a bucket under the drain piping and then pull the handle wide open, let it blow for a second or two and then let the handle snap shut. It is normal for the pipe to drip for a few minutes as all the water drains by gravity but it should stop in five minutes or so. If it still drips then it needs to be replaced.
#4
02-10-18, 04:43 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 38 Upvotes
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Some people barely open the safety valve, the noise and steam scare them or something. You MUST open it fully and let it blow for a full second or more to flush the crap off of the seat. Sometimes it takes several tries and sometimes the seat or disc is already damaged and will require valve replacement. This is NOT justification for never testing the safety valve.
Back when I was gainfully employed we would pull the safety valve handles on the large boilers and let them blow for a full five seconds. People new to the job were almost always scared by the noise and had to do it several times before getting used to it. Sometimes I would stand with them and put my hand over theirs to make sure they understood what fully open on the handle felt (and sounded) like.
For my own water heater I keep a spare valve on hand for the rare occasion when one does not properly re-seat after testing. I have never had to use the spare but at less than $10 it is cheap insurance. I test twice a year.
Back when I was gainfully employed we would pull the safety valve handles on the large boilers and let them blow for a full five seconds. People new to the job were almost always scared by the noise and had to do it several times before getting used to it. Sometimes I would stand with them and put my hand over theirs to make sure they understood what fully open on the handle felt (and sounded) like.
For my own water heater I keep a spare valve on hand for the rare occasion when one does not properly re-seat after testing. I have never had to use the spare but at less than $10 it is cheap insurance. I test twice a year.
#5
02-12-18, 07:29 AM
I checked this morning and no more dripping 
Mine hardly makes any noise at all. I really need to yank out all of this polybutylene and replace with Pex before tragedy strikes again. I've already done the upper floors but haven't gotten around to doing the basement.
Mine hardly makes any noise at all. I really need to yank out all of this polybutylene and replace with Pex before tragedy strikes again. I've already done the upper floors but haven't gotten around to doing the basement.
