put a clock on the water heater

[n175h]

I put an accumulator clock on my water heater Friday. It is wired in parallel with the gas valve coil. When the coil is powered the clock adds time. Checked it Sunday morning and it was on 2.2hrs on Saturday. 2.2 X 700000btu's/hr divided by 100000 x $10 per therm equals $15.40 worth of gas.

Am I figuring this right? I want to know how much the hot water costs me. Anyone else do something like this?

Thanks,

David

[David]

I have not, but I have been trying to calculate my dryer gas cost.

My methods are a bit more primative. I count dryer income, and them compare that to propane usage. While it doesn't account for the water heater, I should have a good estimate.

However, I would be interested in the accum. clock model info.

Thanks,
David S.

[CharlieS]

Yes, I do the same. I have hour meters (24 volt) wired in parallel with the gas valve. Not only does it allow me to track my actual heater usage, but it also helped me to find a problem when the hours were suddenly very high. Because I have two heaters, I wasn't aware that one wasn't firing correctly and the timer clued me in.

My time runs from 1.6 hours per day in the summer (2 - 270 K heaters, total time for both) to about 4.5 in the winter. Incoming water temp makes a huge difference. You can also easily track the cost of running at 130 versus 120, etc.

But then again, I'm a numbers guy and really like to know what the numbers can tell me.

Charlie

[William]

Where are you guys getting the timers and how do you wire them up?

[n175h]

On my heater, the valve controls are all 24v ac. I bought a relay with a 24v coil and hooked one coil terminal to the main valve terminal. The other side to the 24v neutral.

The relay contacts close a 110 volt switched line to an accumulating hour meter. When the gas valve is powered, the relay coil is powered, the relay contacts close and send 110v to the timer.

I bought both parts at Grainger, about $60 for the clock and relay.

The reason I installed this is to determine the viability of adding solar heating. I've found a moderately efficient batch heating engineered system that can be made from discarded 40 gallon water heater tanks, but the enclosures and plumbing costs are still a money issue. I'm in deep south Texas and can use a closed loop active system without the fear of freezing. The rising cost of gas is making such a system more and more attractive.

David