Have RV Questions? Ask an RV Mechanic Online.
Hi my name is Robert......
Do you have DC voltage on the yellow wire coming from the circuit board? The yellow wire should carry 12 volts and signal the relay..... IF you have no DC voltage on that wire but ave voltage on the White wire going to the board from the switch then the circuit board is at fault. Robert
The way that relay works is when you hit the switch it sends voltage to the circuit board, the circuit board then sends 12 volts dc on a yellow wire from the board. That wire should have voltage to trigger the relay. IF the element is good then it is an issue with the 12 volts or circuit board, hope this makes sense, if you need a wiring diagram let me know. 11.29 volts is a bit low so I would try and see what it does around 12-13 volts and see if it works...... Robert
I would see what happens around 12.5 volts, that relay should be clicking over, I almost wonder if you got a bad relay. On some atwoods they also had a high limit cutoff and if you had that you would see one wire on the element going to a disc or button, make sure that if you see that it is not tripped. The main AC power should come from the main breaker panel, I thought I saw you had 110 at the relay... Which means the supply should not be the issue. Robert
Yes you can use another source. This one is a bit of a head scratcher
Yes you want to check for AC power on the wires for the element to see if the relay is switching and allow the AC power to go to the water heater. Robert
Boy this one is difficult as it sounds like the new relay is not working allow the AC voltage to switch. I am pretty sure I know the exact model number of this water heater but can you verify that for me? Only one that Atwood makes uses that relay on the back. Also have you checked the voltage on the wires from the relay to the element?
Running out of ideas on this, it is sounding like maybe you got a bad relay if the yellow wire is carrying voltage to the relay. A few other things I would check Click HERE and see page 11 and 12, make sure you do not have a high limiot cutout between the element and relay, I did not see one on the diagram but I would think they would have some type of protection for the AC side. Look also on page 25 this is what it says...
No power through relay (electric). • Confirm AC present. • Confirm DC through yellow wire (YLW 2). • Check AC into element. No power, replace relay. • Power into element from relay (no heat), replace element.....
My goal is for you to be satisfied with my efforts, If you would like to try another expert please let me know I only get credit when you select a rating... Robert
IF you have 12 volts on that wire the relay should be allowing the AC power to the element. I am not sure what else to try on this. Normally you would hear the relay click when the 12 volts is applied, check your AC connections and make sure the ground from the relay is clean and secure. I keep going back to the diagram on this and the relay should be working if you have the voltage on that yellow wire. Robert
It looks like to me on the print where the relay is that yellow (DC) wire is coming in and then on the other side shows ground,
This one has me baffled, as you should be getting voltage across the relay when 12 volts is applied,.
That is a possibility, sometimes a power converter can put out AC ripple or dirty voltage and the circuit board does not like it the battery also acts as a filter for the converter. I might also have a shop test the circuit board out many shops and RV parts stores have a board tester and can tell if the board is working properly. Please let me know if you need more help.... Robert
The two black wires at the relay are 120 volts for the element, if the contacts were closing in the relay, both black wires should measure 120 volts AC to ground. If the contacts in the relay don’t close then only one black wire from the breaker panel would have 120 volts to ground you should have 120 volts AC going in the relay from one black wire and coming out of the relay to the other black wire to the heating element when the relay switches. Robert
I do not know what else it would be, possible the board it at fault and if you already tried two relays then that might be next. They do fail and if the new one does not do it you would have a backup board. The only other thing that might help is if you can send some pictures of the wiring from the relay to the element. This one is very strange.... Robert
I been in search of a diagram with the pin outs on that relay. The only other thing I can think of is to follow that green ground and make sure you have a good ground, this makes no sense at all to me, if you have 12 volts going to the relay and have AC voltage on one of the black wires the relay should be working, I would check the ground wire make sure no loose connections and where it terminates is grounded. If I find a pin out of the relay I will let you know... Robert
I didn't catch the vice grips when I first looked at...
I do NOT think the control board is bad as you would not be getting voltage on the yellow wire. SO it sounds to me it is a wiring issue or the relay is bad. Not sure on that ground if they are making good contact to the tank then it should be OK, I do not have a diagram on how that relay should be wired, I have been trying to find something, if you wired the same as the old one then it should not be an issue. IF you have AC voltage on one of the blacks, the 12 volts is at the relay then it has to be the relay, the ground or the wiring on the relay..... Robert