Another WH question

[DSurette]

Would it cause any harm to an electric water heater to unplug it for a while, like say for a week or two for vacation when the family is out of town? It seems like such a waste to keep water hot when nobody will be using it for a week or so.
Thanks in advance for replies.

[wrench spinner]

no it wouldnt

[plumberjr]

not at all-
good thinking--save energy

[JERRYMAC]

NO IT DOE'S NOT HURT THE WATER HEATER !
" BUT ' it could hurt your family with bacteria ie; legional that grows in the lukewarm water waiting for you to return and use ! ! !
so if you want to save a few dollars on electric, but end up paying medical bill's
thats up to you ! ! :have-fun:

[plumberjr]

yes thats true--damn your thinking

[Dairylander]

NO IT DOES NOT HURT THE WATER HEATER !
" BUT ' it could hurt your family with bacteria. . .

Chalk up another point for tankless water heaters!!!! ;)

[wrench spinner]

Chalk up another point for tankless water heaters!!!! ;)

yeah the $5 he saves by turning the water heater off when he doenst use it will pay for that tankless in no time!

[PLUMBER RICK]

electric tank heaters are maybe less than 10% for my customers.

but i do have a customer with a 80 gallon electric. he installed a water heater timer to shut off at night.

i forgot what he said his savings were, but we get billed every 2 months and it was enough to make it pay off immediately.

there is a timer made by "intermatic" designed for water heaters. basically it has an external tripper that allows you to turn on or off without opening the timer box.

i think it's a water heater watchdog or watt saver?

otherwise a t102 will work.

rick.

[DSurette]

Thanks for the replies. Guess its not such a good idea if the water won't stay safe. But Jerrymac, you got me wondering about Legoinairs disease. When I lived in Florida we lost power twice due to hurricanes and both times it was for about two weeks. This was pretty much widespread over a large area and there were never any reported cases after power was restored.

Rick, I had an Intermatic timer on the WH in Florida. Had it come on for two hours at 5 AM and again for 2 hours at about 6 PM. I don't know if it helped the power bill much, but it made me feel good. The best thing I ever did for our power bill was move to Tennessee. It's about half what we were paying in Florida and we have a bigger house. Add that to much lower property taxes and home owners insurance about one fifth of what it is in Florida. I wonder if OSC is happy with his move to Tennessee?

[NHMaster3015]

Want the crap scared out of you? Go to www.watts.com (http://www.watts.com) and fish the site for legionella bacteria or disease. They have a couple of vids on there that will really open your eyes. Just keeping a water heater at 120 is not enough. The bacterial can propogate in the downstream piping. They recommend keeping the tank at 140 and installing point of use tempering valves at all necessary fixtures.

[DuckButter]

Want the crap scared out of you? Go to www.watts.com (http://www.watts.com) and fish the site for legionella bacteria or disease. They have a couple of vids on there that will really open your eyes. Just keeping a water heater at 120 is not enough. The bacterial can propogate in the downstream piping. They recommend keeping the tank at 140 and installing point of use tempering valves at all necessary fixtures.
If I recall, the Nashua inspector requires 160 with tempering for this reason.

Synical thought...bet that keeps the locals real busy with replacements.

[myakka]

I'm guessing in Florida, with the amount of chlorine in the water we dont have to worry about legionella( I think pool water has less chlorine). DSurette's statement about taxes and insurance in Florida is dead on. I'm paying 1/5th the taxes in Colorado for more services.
Mike

[JCsPlumbing]

If Legionnaires is such a threat, why don't they write it into the code to set temps at 140+ degrees for all storage type heaters with a thermostatic valve?

Also, why doesnt it develop in the long runs of hot water piping? Around the radiant heated area where temps could be in the range for developing the bacteria even if the setting is 140+?

Seriously asking.

J.C.

[Masterplumb]

If Legionnaires is such a threat, why don't they write it into the code to set temps at 140+ degrees for all storage type heaters with a thermostatic valve?

Also, why doesnt it develop in the long runs of hot water piping? Around the radiant heated area where temps could be in the range for developing the bacteria even if the setting is 140+?

Seriously asking.

J.C.

Good point JC. I always wondered that too.

I think it also has to do with stagnation.

[NHMaster3015]

legionella bacteria is not effected by chlorine except in contrations that are high enough to be toxic or corrosive.

[NHMaster3015]

Good point JC. I always wondered that too.

I think it also has to do with stagnation.

Even raising the temperature to 160 or higher does not kill the bacteria that are living in the pipes downstream of the heater. For years we thought that if we just upped the tank temp it would solve the problem but it seems legionella can and do propogate in the piping.
So it seems the only way to solve the problem is to keep the temps very high and temper at the fixture.

[Masterplumb]

Crank that puppy all the way up. If the T&P ain't blowing every once in a while, its not hot enough!!

Devine is that you?

[boillerman]

If Legionnaires is such a threat, why don't they write it into the code to set temps at 140+ degrees for all storage type heaters with a thermostatic valve?

Also, why doesnt it develop in the long runs of hot water piping? Around the radiant heated area where temps could be in the range for developing the bacteria even if the setting is 140+?

Seriously asking.

J.C.
Why do you think they require backflow protection on the feed lines to closed heating systems? And why do you think code forbids running a heating line with your recirc line to your water heater? Stagnant water breeds bacteria in the pipes.

I doubt turning down the water heater for a week would do it though. No expert in the matter, but people turn down there W/H's all the time. Hence the 'vacation' setting on most gas thermostats? Haven't checked out the link yet, maybe that will change my mind.

[stokefire7]

:rotflmao1::bravo:Devine is that you?

[ridgidpipe]

I usually will recommend shutting down the water main when going on a vacation to most homeowners
To be honest I never thought about the forming of legionella in the water heater if the temp was turned down while they were away
So if it is an electric water heater would you recommend draining the tank after the power supply is turned off to it ?
or with a gas water heater after the gas valve is turned off ?
I do a lot of winterizations in my area where I drain the whole sytem down if the house is vacant for any period of time to prevent any possible damage from being caused by any leaks that might happen when no one is around
So I guess what I am wondering is if someone goes away for a week or two should they just shut off the main line and let the water heater function as normal or should the go through the whole process of draing the whole system down ?