Electric water heater kicking off

Electric water heater kicking off

PostBy: mozz On: Sat Sep 20, 2008 8:55 pm

Today noticed the kitchen hot water was only warm. I have the refurbed coal boiler plumbed before the new Rheem elec. water heater. I thought the breaker had tripped but it was ok. Seems these new elec. water heaters have a temp sensor in case of over heating. My coal boiler does have a mixing valve across the coil (brass gate valve) which i have 3/4 or more shut. I had it about 1/2 way open as a starting point with the new install but the boiler was firing when the washing machine was on using hot water. The input is well water and it's pretty damm cold. Its' a manual red reset button which you have to remove the 2 screws to take off the panel, pull out a handful of insulation, then reset the button, click. So, my options are, ?????? open the mixing valve more so the water flowing into the elec. water heater is colder(defeats the purpose of sorts)???? or turn up the temperature on the water heater elements(seperate thermostats for upper and lower) and get higher standby losses at nighttime ??? or jumper the high limit thermo out of the circuit ??? I have one of those cheapo infrared temp sensors from Harbor Freight which works ok (i guess) so i am going to see if i can get an idea what temp the water is coming out of the coal water coil. When it gets cold out, and my boiler is making steam heat, i'm sure the DHW temp is going to be even more?

The water heater is equipped with a
combination thermostat and temperature
limiting control (ECO) that is located
above the heating element in contact with
the tank surface. If for any reason the water
temperature becomes excessively high, the
temperature limiting control (ECO) breaks
the power circuit to the heating element.
Once the control opens, it must be reset
manually.
mozz
 
Stoker Coal Boiler: Axeman Anderson 1982 AA-130 Steam

Re: Electric water heater kicking off

PostBy: Wood'nCoal On: Sat Sep 20, 2008 9:27 pm

My now departed electric hot water heater had the hi-temp cutoff. Can you install a small circulator and a bypass From the outlet of the electric tank back to the inlet side of the domestic water line at the AA? That way you can maintain a tank full of hot water and shut off the power to the tank heaters. You might have to install a check valve in the cold water line to the coils in the AA to prevent a flow reversal when a cold water tap is opened. Also an expansion tank on the outlet side of the electric tank is a good idea. Just a half-thought-out idea.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Electric water heater kicking off

PostBy: Freddy On: Sat Sep 20, 2008 9:45 pm

Soooo, You're using the coil in the Axeman to gravity heat water in the electric tank? How about... just have the cold go through the coil, then to the tank. It will just get heated once, not over & over. Of course the electric will kick in to make up for standby loss. Just thinking out loud.
Freddy
 
Stoker Coal Boiler: Axeman Anderson 130 (pea)
Hot Air Coal Stoker Stove: Reading piece o' junk in the barn (rice)
Coal Size/Type: Pea size, Superior, deep mined


Re: Electric water heater kicking off

PostBy: mozz On: Sat Sep 20, 2008 9:48 pm

"Soooo, You're using the coil in the Axeman to gravity heat water in the electric tank? How about... just have the cold go through the coil, then to the tank."
I don't know what you mean by gravity heating, i'm using the Axeman to preheat the water before the elec tank. It's too hot and making the elec. pop it's high limit. I opened the mixing gate valve to 50% so the water coming out of the Axeman is cooler now. I don't like running pumps or circulators anything 24/7. I keep my electric bill low, has never been more than $50/month except when the direct vent on the leisure line is running 24/7 as in last year.
Cold water goes into the coal boiler coil, then from there it goes to the elec. water heater.
Last edited by mozz on Sat Sep 20, 2008 10:07 pm, edited 1 time in total.
mozz
 
Stoker Coal Boiler: Axeman Anderson 1982 AA-130 Steam

Re: Electric water heater kicking off

PostBy: Wood'nCoal On: Sat Sep 20, 2008 9:50 pm

I understand that, that's why I suggested the bypass loop to keep the tank hot so you don't need to keep the power to the tank heaters on. Under demand the coils in the AA will generate the hot water required.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Electric water heater kicking off

PostBy: Freddy On: Sun Sep 21, 2008 6:54 am

Ahhh, I understand now. So, ignore my comments & go from here.

It took a double read, but now I understand WoodnCoal's idea also. If you implement his idea, it might actually save you some electricity.

Right now the electric water heat is using some electricity. If it weren't you'd never know the limit had tripped. W&Coals's idea is to never use the electric heater, just use it's tank. Have a circulator pump plumbed in, when the electric tank calls for water to be heated, the pump comes on and circulates water through the AA coil, heating, or reheating, the tank. When you use water, it would do as it does now, go through the coil first. It would be a project. You'd need a pump, aquastat, mixing valve (maybe you already have one). I haven't thought it all the way through, but it would be cool! Maybe someone else can fill in details.
Freddy
 
Stoker Coal Boiler: Axeman Anderson 130 (pea)
Hot Air Coal Stoker Stove: Reading piece o' junk in the barn (rice)
Coal Size/Type: Pea size, Superior, deep mined

Re: Electric water heater kicking off

PostBy: Razzler On: Sun Sep 21, 2008 9:16 am

Put a pump in the line, put an aquastat in the tank. Set the stat for the temp you want and it will keep the tank at that temperature you have it set at. All the HOT water you want. turn off the electric to the hot water tank! :eek2:
Razzler
 
Stoker Coal Boiler: EFM DF520
Coal Size/Type: Buck

Re: Electric water heater kicking off

PostBy: LsFarm On: Sun Sep 21, 2008 9:43 am

The small circulators burn only about .5 amps, about like a 50-60 watt lightbulb.. even the very common Taco 007 pump only burns .78 amps, so about like a 100 watt bulb.. an hour of your heating element in the tank is probably equal to a whole month of the pump running.

An aquastat in the top of the electric tank or it's plumbing to control the pump will eliminate most of the pump's electic use.

Greg L.

.
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

Re: Electric water heater kicking off

PostBy: Wood'nCoal On: Sun Sep 21, 2008 10:07 am

I have another idea :idea: .
If the DHW coil in the AA is supplying your hot water why do you need the electric water heater at all? If the AA can supply all the hot water you need dump the tank. Problem solved.

If you plan on shutting down the AA in the summer then fit valves on the inlet and outlet pipes to the tank and install a bypass with a valve just before the valves. you can isolate the tank and bypass it when the AA is firing, close the bypass valve and use the tank when the AA is out.

If ideas were gold I'd be rich. :|
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Electric water heater kicking off

PostBy: BIG BEAM On: Mon Sep 22, 2008 7:33 pm

You have to figure out if it's triping the safty on the water heater because the water from the boiler is to hot ,or has one of the thermostats on the water heater gone bad.Very often when they go bad they fuse closed and the water heater will shut off on saftey.The way they work is the top element is energized first then when it's satisfied the bottom element is energized(with a cold tank)The saftey on electric water heaters "trip" at about 180*.
DON
BIG BEAM
 
Stove/Furnace Make: USS Hot blast
Stove/Furnace Model: 1557M

Re: Electric water heater kicking off

PostBy: mozz On: Mon Sep 22, 2008 8:32 pm

Thanks for all the ideas. The elec water tank is new so i don't think there is any shorting of the elements. I opened the mixing valve on the AA so the water going into the elec tank is cooler now, no problems so far. I have it plumbed with valves on both the AA and the elec so in case i have to shut down the coal, i still have hot water. "The saftey on electric water heaters "trip" at about 180*." The boiler is set up for steam, the low setting on the aquastat is at 190ish. The water coming out of the coil was probably about 180. When i had the mixing valve almost closed, the copper pipe going to the water heater was pretty hot, you couldn't hold your hand on it.
mozz
 
Stoker Coal Boiler: Axeman Anderson 1982 AA-130 Steam