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Topic: Atwood water heater, 120V issues. (Read 468 times) previous topic - next topic

Atwood water heater, 120V issues.

Greetings,
 My Atwood water heater (as far as I know,  original) will not heat on 120V.
 I was wondering what voltage I should get when measuring across the 2 terminals inside the rubber boot connecting to the element.
 Across both I get 0, but just on one I get 6V.  That's strange.
 Should I just get a new element?
In restless dreams I walked alone.
Narrow streets of cobblestone.


'93 U225
Build 4337
'14 CRV Toad

Re: Atwood water heater, 120V issues.

Reply #1 –
Are you sure it's not a sensor? The PO added a "hot rod" to ours. It's down at the bottom where the drain was. It trips the GFI if any rain gets in.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Atwood water heater, 120V issues.

Reply #2 –
Whether the water gets hot or not, you should have 110 AC at the element. If no 110 there is a problem somewhere else. If you get 110 then the element is bad. On the back where the element is are 2 thermal breakers that control the 110. I would start there. You didn't specify if it has an add on hott rod or not, so I'm assuming not.
1994 U280, Build 4490
Deming, NM.

Re: Atwood water heater, 120V issues.

Reply #3 –
Quote from: Pierce & Gaylie Stewart –
Are you sure it's not a sensor? The PO added a "hot rod" to ours. It's down at the bottom where the drain was. It trips the GFI if any rain gets in.

Pierce
Just started looking at it.
All is on the table, but no breakers or GFI tripped
In restless dreams I walked alone.
Narrow streets of cobblestone.


'93 U225
Build 4337
'14 CRV Toad

Re: Atwood water heater, 120V issues.

Reply #4 –
Electric heating elements are tested by removing both 110v ac wires, and then measuring resistance using ohms scale on multimeter.

Electric 110v wires will measure about 110 - 120v WHEN power source (breaker) is on AND thermostat switch is closed (calling for heat).

Re: Atwood water heater, 120V issues.

Reply #5 –
Quote from: Barry & Cindy –
Electric heating elements are tested by removing both 110v ac wires, and then measuring resistance using ohms scale on multimeter.

Electric 110v wires will measure about 110 - 120v WHEN power source (breaker) is on AND thermostat switch is closed (calling for heat).
No water in the heater, I drained it all before working on it.
I wonder if having an empty tank makes a difference?
In restless dreams I walked alone.
Narrow streets of cobblestone.


'93 U225
Build 4337
'14 CRV Toad

Re: Atwood water heater, 120V issues.

Reply #6 –
Quote from: Barry & Cindy –
Electric heating elements are tested by removing both 110v ac wires, and then measuring resistance using ohms scale on multimeter.

Electric 110v wires will measure about 110 - 120v WHEN power source (breaker) is on AND thermostat switch is closed (calling for heat).

When testing element, what ohm reading?
In restless dreams I walked alone.
Narrow streets of cobblestone.


'93 U225
Build 4337
'14 CRV Toad

Re: Atwood water heater, 120V issues.

Reply #7 –
I guess you know this already but if you applied power to the water heater with no water in it, the element will burn out very quickly.
I normally check a water heater element with a voltmeter and ampmeter. If no voltage 120v ( or 240 if not a 120 unit) at the element then check voltage through the T-stat. Make sure T-stat is passing power to the element. If 120v at the element then use the ampmeter to check for current, amount of current will depend on the wattage of the element but should be at least 8 amps for a 1000 W heater. As stated above an ohm meter check will work if no power is applied and you know the size of the element. A partially burnt out element will show continuity but the resistance will be too high to pass enough current to heat the water.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Atwood water heater, 120V issues. Update

Reply #8 –
 New info.
Turns out that my H2O heater has a "hotrod" element, not the standard element.
 This explains the difference in wiring as it appears that the hot rod is connected directly to 120V with no thermostat involved.
 I am showing 0 ohms at the connector.  Is this proper?

EDIT: Per mfgr. website, it should show some resistance between connector pins (IIRC, between 20-30 ohms), mine has no resistance. New part on order.
In restless dreams I walked alone.
Narrow streets of cobblestone.


'93 U225
Build 4337
'14 CRV Toad

Re: Atwood water heater, 120V issues.

Reply #9 –
Quote from: Moby –
New info.
Turns out that my H2O heater has a "hotrod" element, not the standard element.
 This explains the difference in wiring as it appears that the hot rod is connected directly to 120V with no thermostat involved.
 I am showing 0 ohms at the connector.  Is this proper?

EDIT: Per mfgr. website, it should show some resistance between connector pins (IIRC, between 20-30 ohms), mine has no resistance. New part on order.
With a Hott Rod ohms makes no difference. If you HAVE 110V at the appliance and no hot water then replace the rod. If you have NO 110 at the appliance you have a problem with your electricity that needs to be addressed.
1994 U280, Build 4490
Deming, NM.
 

Re: Atwood water heater, 120V issues.

Reply #10 –
FWIW.
From mfgr web page.
In restless dreams I walked alone.
Narrow streets of cobblestone.


'93 U225
Build 4337
'14 CRV Toad