Water heater leak at safety valve

[andre]

Hi when I open my water heater with the 120 volts current there are some water comes from the safety valve. I check for a post about that but don't find. Maybe the water comes too hot or the safety valve is faulty? My tank is a seaward 6 gallons. Do you have an idea. Thank you.

[Stu Jackson]

Andre,

Yes, don't leave the heater on via electrical power for more than 30 to 45 minutes.  You'll get plenty of hot water, and if you need more, just turn it back on.

Some might/will say your thermostat is faulty or your pressure relief valve is faulty.  It's rare for those things to happen.  Just keep the water temperature reasonable, so that the thermostat or PRV do not have to kick in.

[Ron Hill]

Andre : You can change your pressure relief valve.  I wrote an article in the Mainsheet tech notes on that very topic. 
You can get a new PR Valve at a hardware store!!

A thought

[andre]

Thank you

[Geoffreykwright]

Andre,

Yes, don't leave the heater on via electrical power for more than 30 to 45 minutes.  You'll get plenty of hot water, and if you need more, just turn it back on.

Stu - is this a general rule?  I just leave the water heater on full time (when I am on shore power).  Should I be turning it off?

[Noah]

I believe that is Stu's "general rule". Perhaps contact Sure Marine Service, who sell, service, and supply parts for that brand and other, and get their professional opinion.
https://www.suremarineservice.com/

[Stu Jackson]

Andre,

Yes, don't leave the heater on via electrical power for more than 30 to 45 minutes.  You'll get plenty of hot water, and if you need more, just turn it back on.

Stu - is this a general rule?  I just leave the water heater on full time (when I am on shore power).  Should I be turning it off?

I do.  I find it's just good management.  In one day I find it hard to use all the hot water in the tank.  Just start over the next day.  If I run it after washing the dinner dishes for a short time, I still have hot water the next morning.

I find that stuff last longer if you don't use them when not necessary.

Call it Stu's Rule. 

Your boat, your choice. 

[Geoffreykwright]

Thanks Stu.  Makes sense.

[Ron Hill]

Guys : LOOK AT IT THIS WAY  - You are only heating 6 gallons of water that is already at the outside ambient temperature !!!
If you had run the engine the HW heater water temp is even higher!! 

30 minutes is more than long enough to have the shore power AC ON!!

A thought

[Stu Jackson]

Ron's right.

I found a big difference when I moved from San Francisco to British Columbia.

57F to 47F water temperature took 10 minutes longer to heat by electricity to "reasonable" hot water.

Now all I have to do is figure out how to tell you that in Centigrade. 

I've only lived here for four years.

[Noah]

I believe Stu's "just turn off the electric heating element after 15-30 mins." is only a bandaid solution for the electric side. If you have a faulty thermostat or pressure relief valve you will probably still have the pressure valve blowing problem while motoring. If the components are working properly, the relief valve shouldn't blow. I would try and fix the root problem.

[KWKloeber]

I would try and fix the root problem.

A relief valve isn't supposed to blow at normal water temps.  Fix it (the problem. not the symptom)  Are you sure it's relieving, or just leaky at dock and motoring?

If you have a leaky potable water pump or one that won't cycle off -- do yah simply keep cycling the breaker whenever you want water? 

[Stu Jackson]

I believe Stu's "just turn off the electric heating element after 15-30 mins." is only a bandaid solution for the electric side. If you have a faulty thermostat or pressure relief valve you will probably still have the pressure valve blowing problem while motoring. If the components are working properly, the relief valve shouldn't blow. I would try and fix the root problem.

Noah, no, it's not.  I believe it is just good practice for not running something unnecessarily.  Ken's right, if the thermostat and PRV are working properly, they should keep the temperature within limits and not blow the PRV whether you keep the electricity on all the time or not.  If the PRV blows off, for whatever reason, it can be replaced.  Many people fiddle with the lever, not recognizing that by doing that they could have lodged a small particle in the seat behind the lever and kept the PRV from closing.  It's easy enough to replace (if you can get to it! ).

[Ron Hill]

Guys : I've posted this before!!  The pressure relief valve is NOT a drain valve - I've never had a relief valve reseat and not leak if I've ever opened it!!  Seems the smallest piece of anything will cause it to not seat and then leak a drip or two.   
 
Learned this from a plumber and experience with W heaters at home. 

As for the length of time to leave the AC heater element ON?  Like any electrical filament the longer it's ON - the shorter its life !!

A few thoughts