Anyone familiar with a ‘hot wire’ oven relay?

[ectofix]

Nope.  I’ve no clue what a “hot wire” relay is. To me, that sounds like a nickname.

 

Kinda like me getting a service call to fix someone’s fish fryer or their potato oven.

 

Makes me think of a story:

A local BBQ restaurateur called me to fix his flatbed smoker (MY description).   His name was Bill.  I’d never seen a smoker like this one before…or since.  Never heard of the manufacturer either.  He had four of those smokers, but just needed this one repaired.

The smoker was large in breadth and depth – but single level.  A huge hinged lid covered it all.  A simple control box to one side.  If I recall correctly, a tstat combined with a timer would slowly cycle the heat supplied by electric heating elements.

 

Bill was obviously one of those owner/operators who had to provide a dissertation to me on why he called me there for service.  He already knew what was wrong from talking with the manufacturer and he explained to me that the “knockers” need replaced.

 

KNOCKERS?  O-k-a-y…  I think I’m going to learn something new today.  As it was though, I never asked him what a “knocker” is.  I’m a technician and I should already know that…

 

So, he left me to it and I went to work exploring this interestingly complicated wiring setup between the thermostat, a timer and a contactor.  I remember REALLY thinking I should look the TIMER over, since that’s what KNOCKS the heat on and off – RIGHT?

 

I got so wrapped around that and the twisted looking wiring setup that it took me entirely too long to figure that the 3-pole CONTACTOR had a bad leg.  I double-checked that and – YUP!  Needs a contactor.

 

It was a general-purpose contactor, but not of the rating that I had on my truck. So I went and got Bill.  I explained to him what component needs replaced and that a vendor just around the corner sells them.

 

He asked “What’s a contactor?”  So, I removed the cover and showed him.  He said, “Oh!  The KNOCKERS!  That’s what I told you before.  It needs the KNOCKERS replaced!”

[galley4u]

In this case, it is a relay for the bake and broil elements in the range. When heat is called for, a high-resistance wire inside the relay heats and expands, leveraging the contacts closed. I was hoping someone had an encyclopedic knowledge of them, so that I could be sure about replacing the ones in my Thermador range. Thanks!

[ectofix]

Ah!  You made me Google it.  So that IS its name and looks like this:

 

 

As far as I know, that part is something exclusive to domestic appliances.  I’ve never seen one of those in any commercial appliances.  That’s what I work on – commercial cooking stuff, as most who come here do as well.

[galley4u]

thanks — this range is a Thermador, with a 12″ oven, a 30″ oven, and a flat top (electric), plus four open burners and a char broiler (gas). At this point everything works except for the broil elements, which actually do heat momentarily but then stop. The contacts inside the ‘hot wire relays’ (one per oven) power both the H1 and the H2 terminals when either broil or bake is selected. It seems the contact on the bake side is good, and not so good on the broil side. But a bit of a puzzle to diagnose.