Chad A 14 Report post Posted February 9, 2012 Ok here is what I have going on. I had to replace the thermoswitch which controls the temp of the hot water. The old one was rusted and was not working. So I get the new switch and I mount it to the outlet T from the burner. I checked it for continuity and it is working fine. When I connect the white and black wires to it the burner does not turn on. If I bypass the switch all together in the junction box the burner fires up and works. It is a Whitco 5030 DPO I have the wiring diagram for the unit and everything is hooked up right. But just with the thermo in place it doesn't work. Here is a Diagram of the way it is suppose to be and in the bypass. The Bypass is the only way it works. Thanks for any insight. Chad Share this post Link to post Share on other sites
Jerry 24 Report post Posted February 11, 2012 (edited) You have a defective switch, or it is the normally open (or OFF) version, instead of normally closed (aka.. normally ON). Edited February 11, 2012 by Jerry Share this post Link to post Share on other sites
Chad A 14 Report post Posted February 11, 2012 Well it is a thermostat switch so it is on as long as the temp is not up on the burner. Part Number is Fenwal 30000-048 50-250F adjustable switch. Share this post Link to post Share on other sites
Chad A 14 Report post Posted February 11, 2012 ok here is the deal. The switch is brand new, but I have figured out whats going on. I went down to the appliance store and purchased a Hi Limit Thermostat pre set at 150F. I did this to trouble shoot the problem. I have found out that if the resisstance is to high on the switch it will not work inline with the other switches (VAC, Burner, Hi Pressure) The resisstance on the new Fenwal 30000-048 was reading on the average of 25 where the other temp switch I put in place for testing ran below 13. The burner is working now but I can offer a temporary fix to a adjustable thermostat going out. Purchase a pre set Hi limit thermostat switch from you local aplliance dealer. $4 This is ony a temporary fix until you can get a replacement switch. During my search for the Fenwal 30000-048 adjustable thermo switch I have found an alternative replacement for the switch which is Tempco TEB30001 Adjustable thermo switch It is almost 3/4 less in price than the Fenwal and has a life cycle of 100,000 cycles Price is $27 versus the $90 for the Fenwal. Companys that carry the switch: Grainger.com Grainger Industrial Supply buy.gissn.com Radford Brothers Industrial Supply Share this post Link to post Share on other sites
