Any idea what might cause of sound of dripping water and what could cause this? This morning we opened closet where waterheater is located and heard a steady drip drip drip. There is an opening in the floor where the copper pipe runs down below the house from the top of the water heater; the opening is screened to keep out critters and the drip noise made a very distinct drip drip drip noise. The waterheater itself does not appear to have any water leaking from the pipe on top, no water in the pan the waterheater sits in, no water on the floor around it.

We called a plumber to come out in the morning; but checking later and throughout the day, we have not heard anymore dripping. It is very odd that there was such a steady drip drip drip, and then 15 or 20 minutes later, there was no more dripping sound. Have checked periodically thruout the day and no more sound of a drip.

Should we cancel the plumber or have him come out anyway to check? He has a 1 hr minimum. Is it possible this is a one time thing we heard? We are in and out of this closet all the time (it’s a pantry) and we have not heard this noise before. It’s a gas waterheater that has been installed for several years, but appears in good condition. Any thoughts or ideas would be appreciated. I would not be able to crawl under the house to check below the closet, it would be a long distance and I am not able to do this.

Since the drip occurred only in the morning, I would suspect that dew collected on the roof, then when it started to warm it expanded and dripped. Then as the water evaporated the drip stopped. I have seen this happen many times.

Open the burner access door to see any evidence of water or rusting.If there is, the source could be ae the base of the supply or outlet connections at the top of the heater, running down the tank, or condensation.

if this happens again, touch the pipe that goes thru the floor; it is a drain for the temperature/ pressure valve. if the pipe is hot, the t&p valve is being activated. you may have the thermostats set too high or one of them is malfunctioning. if turning them down a few degrees doesn’t fix the problem, your t&p valve may be bad and should be replaced. the drip may be occurring under the house, causing more problems if not corrected.

Thanks, turned out it was the TPR valve (temperature and pressure relief valve) drain line doing what it was supposed to do. Good to know about the other possibility though.

You are exactly right, the plumber was her yesterday and that was exactly what it was; strange we never noticed this in all these years! Ends up we are going to replace the water heater as it is at end of 10 yr life cycle. I never knew all this about the safety release valve, turns out it was operating just as it should. Thanks for your very clear explanation; if I hadn’t had the plumber here already, it would have guided me exactly to finding out the answer.

A couple things come to mind…you say a pipe coming off the water heater and traveling downward into the floor. I think you are talking about the TPR valve (temperature and pressure relief valve)drain line. This valve will open if the temperature in the tank exceeds 210 degrees or if the pressure in the tank exceeds 150 psi. It may be that this valve is partially open to allow water/steam out of the tank…i.e. it may be that the valve is sensing one of these conditions and is operating correctly. What is interesting is that you say you notice it in the morning when nobody was using hot water and the sound goes away after a short time. It may be that the sound goes away because people awake and use some hot water, which will add cold incoming water into the tank, essentially cooling it off and allowing the TPR valve to close. The next time you hear this noise, turn on the hot water at a faucet closest to the water heater and see if the dripping noise stops shortly afterward. The fix for this would be to turn down the thermostat on your water heater and note if you hear a drip the next morning. The other item is you might be getting some condensation off of the tank and falling on the burner, but you would likely hear a “sizzling” sound if this was the case.

I will watch for this and check. We are actually having waterheater replaced next week and a small holding tank installed to take care of the back up; plumber said the amt of water thru the vent is very small and not a problem. I think we are all set. Was surprised the cost of water heaters is so high, but I guess that’s the way of things these days.