My caravan carver heaters pressure relief vale keeps blowing any ideas please

Add a domestic water expansion tank to the cold water line going into the water heater or at the water main coming into the building.

Pressure relief valves open on high temperature as well as high pressure. They do go bad and are replaceable.

Consider calling the plumber. It is not very expensive part and the plumber can change it quickly.

If you just want to do it yourself:

1. Write down the make and model of the water heater.
2. Go to a real plumbing store and buy a new one.
3. Turn off the heat source (the gas or electricity)
4. Turn off the water inlet and open a hot water valve at any sink to take the pressure off the heater.
5. Remove the old relief valve. It may take a long handled wrench.
6. Install the new pressure relief.
7. Close the sink valve.
8. Turn on the water and check for leaks.
9. Turn on the heat source.

Good luck.

Some times a relief valve goes bad. should get professional help.

you can go to get another relief valve because if its dripping its probably bad. if you have a clark supply center nearby, you can get one there! or another plumbing place or water heater supply. you may have to drain out some water to bring the level below the valve. Shut off the power to water heater. If electric, turn gas to pilot setting, if a gas water heater. Cut off water supply to water heater as well. It is not necessary to drain the entire tank. Open a hot water faucet, drain water from tank, drain for approximately three to five minutes. Prepare the new relief valve with Teflon tape. Unscrew the relief valve counter-clockwise with a wrench to remove.
Turn the water supply back on to water heater. Make sure water is running from the open faucet before turning the power back on. good-day!

Hi, it says you are having problems with the relief valve, I am not sure what it is, but they will blow water if the water temperature exceeds its rating and water pressure. Also, says you have a humming every 3 seconds or so in the pipes? This sounds like a classic case of hard water deposits have formed up around the control valve probe that's inserted into the water. Also if the pipes are galvanized and not copper, they will rust up the walls of the pipes over time with deposits also closing of the amount of room for the water to get through. It would really help to know the age of your home and if the water heater is gas or electric? When this happens, you will hear a popping noise at the water heater and you will get air in the pipes that will cause all sorts of noise, humming, growling, the pipes will rattle and with the restricted lines and build up of sediment, the pressure relief valve will let loose to relieve the pressure. If you are having any signs of low and uneven pressures and hot and cold problems, depending on the age of this water heater, you will need to replace it.If it is a gas heater, you will have a round plastic drain knob located at the bottom of the heater. You can turn it ccw all the way open and let the water coming into it from the fill valve on top flush out as much of the sediment as you can. When you have done this, close the valve off to fill it up again and repeat the draining or flushing process. This will also remove any air trapped in the lines. Important! When you are filling the heater if you had shut the fill valve off on top, open the water valve and on the relief valve, pull the lever up to lock it open as this lets all air from the lines out of the heater and the water pipes. If this relief valve is blowing a lot, replace it. Just turn the water valve off on top and use a pipe wrench to turn it ccw to remove it. Look for sediment on the rod to see how much has build up on it. This valve is around $25 and will be cheaper to replace then the heater. The size is 3/4". Temperature range for it to open will be stamped on the old valve. This you can get at any hardware store such as Home Depot, Lowe's, Ace and so on. Pick up a small tub of pipe dope to coat the treads when installing and once it is in, turn water on and raise the lever up as you turn water back on to fill the tank to remove the air. This should solve this problem. Please keep me posted on this and your progress and if you will tell me the age of your home and if its a gas or electric heater this will be helpful if the instructions I have given you do not solve this problem. I do believe it is just trapped air and a faulty pressure relief valve at this point. Please don't forget to rate me as I know you will be kind and please keep me posted as I will check on you as I store your information in my files to look in on at any time I may need.
Sincerely,
Shastalaker7

This called a pressure relief valve, these are meant to blow off and relief pressure if it needs to. These valves do go bad and need to be replaced from time to time.

what is the water pressure on the cold side? You may need to install a pressure reducing valve at the water heater inlet to reduce inlet pressure and keep pop off valve from opening when not needed.

Is there a temp setting like hi,med,or low? That control works like a rheostat. If it is shorted it will keep the elements full powered and you will have this problem. Has the pressure relief vale gone off yet? Make sure it works so you don't have pressure damage to the plumbing . Now back to the thermostat. Try turning it all the way down. If it continues to heat, The rheostat is defective (temp control)

Check the tank drain valve for water there.If you get a good water flow there you know the tank is getting water pressure.Check the first outlet downline from WH and if there is no water there you have a blockage or other problem.If you have to turn off water to tank, remove the outlet pipe ,and check for water flow from tank with in valve on.If no flow, tank is plugged up.
Hope this gets you going.

Hi, it appears you have a defected relief valve. you can try one solution. lift the handle on the relief valve and let some water out. sometimes that can flush out materials thats blocking the stem in the valve. if it's still leaking it must be replace.

If this doesn’t work for you please write back. Thanks,