Sunnen rod heater problem.

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gn69z28
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Sunnen rod heater problem.

Post by gn69z28 »

We have a sunnen CRH-50 rod heater. It's stopped heating. Inside there is a thermo disc. When activation button on front is pushed in the thermo disc switch has power on one side but not the other. If we bypass the switch and connect the two wires together the coil will heat up. So that makes us think the thermo disc switch is bad. Does that sound right? And any idea where to get a replacement switch? Sunnen says no longer available through them. Part number on switch is 49T11. Anyone have any experience with working on one of these things. We do mostly stock engines so 90% of all pistons we get are press fit. Thanks for any help.
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Re: Sunnen rod heater problem.

Post by Dave Koehler »

Bit of a rip but here is one.
https://www.ebay.com/i/362843732597?chn ... q8QAvD_BwE

Edit: oops I don't think that is what you asked for.
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Re: Sunnen rod heater problem.

Post by gn69z28 »

Thanks for your reply but no that's not what I'm looking for. Problem is I'm not really sure if what I'm looking for is the problem. When you push the button in that you just posted the coils don't heat up. And sunnen was no help.
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Re: Sunnen rod heater problem.

Post by Kevin Johnson »

Check your PM
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Re: Sunnen rod heater problem.

Post by gn69z28 »

Thank you. We will look into that.
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Re: Sunnen rod heater problem.

Post by Cris »

I think this is what you are looking for?:

https://www.radwell.com/en-US/Buy/THERM ... ISC/49T11/

It is listed as discontinued, but it appears to be NOS.

It also appears that there are cross references to the switch. Type in 49T11 Switch on Google. Here's one link:

https://www.lintechcomponents.com/produ ... 9024/81439

I am assuming that the thermo switch is mounted on the heated part of the rod heater. Its function would be to be closed (current flows) when the rod heater is turned on and, once it reaches temperature, it opens up to turn off.
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Re: Sunnen rod heater problem.

Post by Cris »

You can also use any similar part as long as the temperature and current rating match. Here's another supplier of similar parts:

https://www.alliedelec.com/product/selc ... lsrc=aw.ds
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Re: Sunnen rod heater problem.

Post by ProPower engines »

Dave Koehler wrote: Thu Apr 23, 2020 12:52 pm Bit of a rip but here is one.
https://www.ebay.com/i/362843732597?chn ... q8QAvD_BwE

Edit: oops I don't think that is what you asked for.
Yes thats retail from sunnen. I have tried to buy stuff from them in the past but they believe any NOS prts are worth the same as the manufacture sold them for retail cost.
very hard seller to dicker with if at all ](*,) ](*,)
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Re: Sunnen rod heater problem.

Post by BillK »

z,
I bypassed both of the discs on mine over 20 years ago and have had absolutely no problems. One of them would open intermittently and the other one had never opened so I just did away with both of them. It doesnt get used as much now days but still a couple of times a week.
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Re: Sunnen rod heater problem.

Post by bentvalves »

push the switch/button in and hold it pegged for a few minutes. Does the coil begin to heat up?
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Re: Sunnen rod heater problem.

Post by gn69z28 »

I'll try holding the button in and see what happens.
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Re: Sunnen rod heater problem.

Post by gn69z28 »

BillK wrote: Thu Apr 23, 2020 6:56 pm z,
I bypassed both of the discs on mine over 20 years ago and have had absolutely no problems. One of them would open intermittently and the other one had never opened so I just did away with both of them. It doesnt get used as much now days but still a couple of times a week.
So that won't overheat the coils and damage them?
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Re: Sunnen rod heater problem.

Post by bentvalves »

my right coil worked, the left did not.

one day I held the left button pegged for like 5 minutes, the unit clicked (reset?) and it has worked ever since.
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Re: Sunnen rod heater problem.

Post by leahymtsps »

Yes thats retail from sunnen. I have tried to buy stuff from them in the past but they believe any NOS prts are worth the same as the manufacture sold them for retail cost.
very hard seller to dicker with if at all ](*,) ](*,)
[/quote]

You do know he's a Sunnen rep. right?

Tom
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Re: Sunnen rod heater problem.

Post by BillK »

gn69z28 wrote: Thu Apr 23, 2020 8:44 pm So that won't overheat the coils and damage them?
Like I said, its been that way for 20 years and have not had a problem yet. If I remember correctly I never used to hear or see them do anything anyway. I imagine if you had one of the timers fail and left it on for an extended period of time that it might hurt one of the coils. Hasn't happened here yet. If i remember correctly when the disc failed back then I tried to get a replacement from Sunnen and they were not even available then.
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