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Timer on Gas Water heater

Posted by thumki (My Page) on
Sun, Oct 1, 06 at 1:34

I know that some folks put timers on their electric water heaters. Would the same technique work on Gas water heaters ?

Is it dangerous to try this ?

Any help or opinion would be appreciated.


Follow-Up Postings:

RE: Timer on Gas Water heater

"Is it dangerous to try this?"

Yes it is dangerous to try this! By allowing the water temperature to drop, you will be creating the proper conditions to allow mold and pathogens, like Legionnaires Disease, to grow in your tank. You and your family will then inhale these as an aerosol when showering. I would hope your familys health and well-being is worth more than the meager savings!


RE: Timer on Gas Water heater

Jeeze is that true or are you just pulling our leg? Doesn't the Chorine etc, slow down those spores? and afterall, it get's heated before you use it again. And the water is circulated out of the water heater every day... please educate me.

RE: Timer on Gas Water heater

I've been doing it for years, no problems.

RE: Timer on Gas Water heater

Setting up a timer for a gas HW might be complicated; it would have to be a newer heater (no pilot light) with piezo-electric starter - then, if they have an electrical connection, probably not too bad, if no electrical connection, then it gets complicated.

I've got an electric HW heater (no gas line nearby), timers help, but only if the household has a REGULAR schedule, to let you schedule off time for after the last shower, until an hour before the first shower.

Legionnaire's disease and mold are NOT likely to be a problem, most home water systems are closed systems (and if on a municipal water supply, are treated with chlorine - an antibacterial)

An aside to fsq4cw - the 130 degree Fahrenheit (about 54 degrees Celsius) isn't high enough to kill most bacteria. But, 130 F is a bit too high for most mammals - they get scalded/burned (to kill bacteria you need 212 F or 100 C - temps I won't run in my home), for safety reasons.

thumki check with a reputable plumber in your area, but disregard the first reply to your question!

A better solution for you, since you have gas hotwater, would most likely be a tankless hot water heater - minimal storage losses - and virtually unlimited HW supply (if sized correctly) - think twice if you have teens at home.

RE: Timer on Gas Water heater

The more efficient way to save money, would be to use Solar panels to preheat the water. Many months the gas would not be needed.

RE: Timer on Gas Water heater

thumki may not have an appropriate exposure to the sun for solar hot water; he is trying to find a way to cut costs(energy use).

I agree that solar is a good way to go (I've had solar space heating since the early eighties), on a limited basis, very old house, 1760'ish, so I've spent time/money insulating and upgrading the windows. The electric HW timer works to reduce cost - if the household has a regular schedule - it works very well; not so well with variables (teenagers/their friends/other guests); learning curve.

I'm (im)patiently waiting for better LED's; very efficient (small surface area - solar collectors and efficient PV units).

Solar is good, if you have the right exposure - if not- conservation is a better bet!


RE: Timer on Gas Water heater

It's simple to put a "timer" on the furnace. Just replace the room thermostat with a programmable one.

The water heater is another story. If it's an electric, one can plug the heater into a timer and then it will only draw current when the timer allows. This is done in some areas with high peak demand, and your power company can advise you. There may be a break on your power bill depending what programs your powwer supplier may have. However, be aware that most electric water heaters are 240v, not 120v, and their current draw is significant. The timer device must be equiped to handle 240 circuits and the current draw. This eliminates most ordinary timers. (In the US, 240 Vac household circuits are really a pair of 120 Vac circuits that are 180 degrees apart from each other.)

If your heater is gas fired, that is another story. I'm not schooled in the required equipment for automatically changing the state of the gas valve/thermostat. In all gas water heaters that I have seen, the gas valve/thermostat is an intergal part of the heater. These valves, however, do have a "pilot" position on the valve knob. Merely turn the valve to "pilot" to prevent the main gas valve from turing on. I do not recommend operating this valve on a regular basis, say one or twice a day. These valves should be operated maybe once per month to maintain an operable condition - refer to the instructions that came with the heater. I suspect that thousands of cycles of moving the control stem will eventually wear the seals. Again, consult the manufacturer.

Also, what ever rigging you apply, it must meet local codes and inspection.

RE: Timer on Gas Water heater

The big box store sell electric water heater timers - they are NOT plug type systems. You must wire them into the line for the water heater - or more correctly it should be wired in by an electrician.

We've been using them on our two water heaters for nearly twenty years. An hour twice a day "ON" time is sufficient for keeping the water hot enough for most uses, like washing hands, and our dishwasher has its own water heating. If more than one person wants a shower or bath, or if it is laundry day, the timers have a push button that will turn the water heater on - the next time the timer is scheduled to turn it off it will in case we forget to turn if off after the extra heavy use is done.

Most modern water heaters are well enough insulated that they will hold their heat for many hours without additional heating cycles, so an hour or two a day is probably all most people need it to be on anyway.

I don't know about timers for gas water heaters - I'm all electric. ;-)


Here is a link that might be useful: Intermatic24 Hour Water Heater Timer 250 Volt

RE: Timer on Gas Water heater

My gas water heater has electronic ignition. To turn it off, you just flip a little light duty toggle switch. I would think that a timer could wired in series with this toggle switch, and would only be handling a small amount of current?

On electric water heaters, the better new ones have Energy Factors around 0.95 -- this would seem to leave little energy for a timer to save? Less than 5%?
I guess older electrics would allow greater savings.


RE: Timer on Gas Water heater

Our water heaters are very old - one is the original one that came with the house in 1979 and we put the other one in about 1988. So they are very inefficient and I'm sure the timers save us money.

I have not checked to see what we'll put in the new house. The builder likes gas tankless water heaters, but I insist on an all electric house (for reasons that have nothing to do with efficiency and that are probably irrational, LOL). I am thinking of putting in a solar water heat system and just using an electric water heater as the tank and for backup.


RE: Timer on Gas Water heater

A word of caution on turning down your water heater.

The old guy next door turned his down .. or perhaps even off when he thought it wasn't needed then turned it on, or up when he wanted to take a shower.

If you do this ... call your health department first...this will cause bacteria to grow in the tank and you can get VERY ILL...

The neighbor contacted ( spelling) Liengonairs desease.

FROM THE TANK.. so be ware....

RE: Timer on Gas Water heater

Our Plumbing Apprenticeship class has been working with the local gas company on a project for two years to study what the actual standby loss is from a gas water heater per month.

Twelve different 60gallon water heaters were all set up side by side with a common header for cold water supply and one hose bibb on the output side of the tanks. Each water heater has a separate gas meter. All twelve water heaters were filled, the the thermostats set to the code maximum of 125degF and left standing with absolutely no load coming off the heaters.

At the end of each month the gas meter is read and the cost of operation is computed at the local residential gas service rate.

In mid summer when the ambient air is warmer the average is $4.44/mo and the average in mid winter when the ambient temps drop to about 45deg at the test site the average is $5.31/mo.

The overall average per anum worked out to $5.02/mo.

The final conclusion was the the standby loss from the water heater is equal to about the price of one cup of coffee from Starbucks, hardly worth the cost of any high tech bells and whistles to try to reduce it.

RE: Timer on Gas Water heater

Lazypup, good information. I used a timer on an electric water heater for several years and saved much money. There were no issues with mold growth or fear of legionnaires. I recall seeing a timer kit years ago for gas water heaters. A few years ago I checked into it and am pretty sure it is no longer made. I also checked into making a timer and found the diy drawback would be the need for a valve to shut the gas off to the burner.

In your test the water heaters had no load. Also, I think temp recovery time is a factor. With a timer I found our household didn't really need hot hot water all the time, which helped reduce use. I think there are some other factors worth noting.

With high gas prices I'd think the water heater manufacturers would include a timer if it was cost effective. Maybe I'm naive. I have to note the price of natural gas isn't regulated where I live, so I'd definitely use a gas water heater timer if one were available.

RE: Timer on Gas Water heater

Don't do it. Rodents will climb down the vent pipe in search of tasty Legionaire's Disease. So they will eat all of that - so no worries about the disease. Unfortunately, the rodents will then poop in your water heater. Is that what you want to shower in?

RE: Timer on Gas Water heater

Gas water heater timers are safe and can save up to 36% on your gas bill, extend the life of your water heater and can be used with most home automated devices. You can also use the timer of your choice with one particular model. See the best on the market. Google Gas Water Heater Timer. This timer has proven technology.

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