State Water Heater Control Problem

Jeff_46

The dead short must be in the box because we didn't power it up. We checked the coil before we even installed it or applied any power to it. Both coils were open.

Jeff_46

WR Tstat Control

We've been running into some State water heaters with White-Rodgers controls that have been giving us fits. I was wondering if anyone else has been having problems with these units.

State model # PR650 NOVT serial # A03101310
White Rodgers control #37C93U 601

We've had a few bad gas pressure switches. We went out to replace the control (it comes with a relay to install which we did per the instructions).

We installed the replacement control. Four days later the 120v coil (not the relay) goes bad. We ordered a replacement control. It was shipped with an open (bad) coil. We ordered another control ... another open 120v coil.

White-Rodgers doesn't list this control. The closest thing on their site is a WR #37C93U 202 which is an OEM for AO Smith.

State was no help at all. They questioned my techs' (and my own) troubleshooting ability saying we must've overlooked something ... that they can't beleive we've had that many bad coils. C'mon ... it's a coil. It's open ... GEEZ. Thanks for the help, State!!!

The customer had enough and wanted a new water heater. We installed the brand we carry and everyone's happy.

However ... we are running into more of these controls. Can anyone shed some light? If there's anyone from State out there ... I'll give you another chance.

Big Ed

Right out of the Box

Seems to be a direct short somewhere.Install a fuse on the load end of the coil and check wiring with your meter..

Glenn Harrison_2

I've had a few of them go bad over the years...

and every one of them was a stuck closed gas pressure switch. It was explained to me that the pressure switch contacts can't handle the amp draw of the inducer if there are any fluctuations in power supply. This is why they provide the relay, to isolate the motor from the pressure switch.

Unfortunatly, I have never had a coil go bad, so I can't really help you with that, other to say you may have a power supply problem, but that wouldn't explain the bad coils from the factory.

Big Ed

It could happen..

It reminded me of a Rezor waste oil heater job a few weeks ago. Unit not working with power at the disconnect. I traced a break to a kixon type limit. On the door it mentioned the high limt is a one shot control. Once it pops you need to find the problem and replace the whole fan and limt unit, which consists of three kixon controls. I noticed the backflow or back pressure manual reset switch was dangling from its perch on the fire inspection door. I ordered the parts , vac the unit (man do they get dirty ) and installed the new fan and limit when it came in a week later... What the @$*& , the dang thing came triggered right out of the box.. Son of a @#$%#. I imagined a bored parts packer sitting there poping the limit and sending them out... I got on the cell to order another. The switch came triggered right out of the box I complained to the parts guy at the other end... Ok we will send another overnight right away. Fedx is picking up in the next hour.. I said great and decided to go back up the ladder and jump out the switch temporary so I could bleed and set up the burner . I jumped the limit and the fan came on, but it did not send juice to the primary control. If you ever work on one , they have wires and juction terminals every where and your poking around hanging off a ladder. To make it short......I found the problem in the oil temperature switch. Fried with a hole in it .... I realized The limit I thought was bad, was the fan switched and the new part and the old part were still good... Hello Mr parts guy ....ahh .....I want to change that order....I hope Fedx is running late...


Not saying that your controls are not bad or they could have had problems in the factory. What I am saying is sometimes as a serviceman you need to look further or from a different angle. Ever have problems getting a bolt or nut started . You could be trying for a half hour, you give up and your helper gets it in one shot... Good luck