# Converting Robertshaw Gas Valve 7100 DER-S7C



## Adam_M (Feb 4, 2011)

Me I tend to only install honeywell gas valves, they have a nice conversion chart to tell you if your coming from Robertshaw or anything else.


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## mikefrommi (Mar 5, 2011)

Forgot to mention. Any references to the ign. Controller all lead back to the same part wether it be Robertshaw or Honeywell. Most say Robertshaw/Honeywell in the reference. Made me think they were the same. Per my other thread on the 7200 - I had enough run around and just called Robershaw directly. Sales had me at wits end. Looking back now I would have checked with HW first. Hard enough to keep up on the electrical side. HVAC = I'm lost on who owns who. But I will say in the hrs of reading that I did that Honeywell was the best talked about by all the mods as well as the subs. I just wanted a darn valve....


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## hvactech126 (Nov 11, 2010)

Get that furnace looked at by a PRO to ensure the Heat exchanger is not cracked!


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## mikefrommi (Mar 5, 2011)

Good idea. We have a 5' lighted video scope at work. I'll bring it home and run it up inside to check. I did brush and vacuum it all out - as well as the burners when I did the valve. I didn't see anything from the front. The scope can feed right up inside. Is there a place where the cracking usually occurs? I'd assume above the flame of each burner where the heat is at it's highest.... Thanks for your input.


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## Marty S. (Oct 31, 2009)

Typical crack location on that furnace is on the back where it first narrows. It will look like a 1-2" rust line next to the seam.


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## hvactech126 (Nov 11, 2010)

again, have a PRO check it even if you don't see it, because you are not attuned to know exactly what you are looking for.


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## hvaclover (Oct 2, 2008)

mikefrommi said:


> Hello,
> The following took several days and much more time than I wanted for the 45min actual conversion. I hope this will help others:
> 
> Furnace = Lennox Whisper Heat = G20 Series Q3-4E-100-1 (100,000 BTU)
> ...


 Congratulations.
You are the only living human to take a simple gas valve and make it sound as complicated as the science that went into the
Manhattan project:thumbsup::whistling2:


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## mikefrommi (Mar 5, 2011)

hvaclover said:


> Congratulations.
> You are the only living human to take a simple gas valve and make it sound as complicated as the science that went into the
> Manhattan project:thumbsup::whistling2:


Complicated???? Maybe to you:wink: To a DIYer - It's everything they need to know to do the job and not make additional purchases. Nothing more - nothing less! Let's not misinterpret informational and complicated. If I had posted this in the Pro forum - I could see where your coming from. But over here you sound like a Pro who's getting money taken out of their pocket. And I noticed you also didn't answer my reply as to where the cracks show up. I do these post on the electrical side all the time and get praise from the mods. Then again, usually when a person has as many posts as you....well we all know what that means! Or you'd be a MOD. Thanks for your "help"

Thanks Marty!


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## mikefrommi (Mar 5, 2011)

hvactech126 said:


> again, have a PRO check it even if you don't see it, because you are not attuned to know exactly what you are looking for.


Hey, I stopped by a local shop and the fella was nice enough to bring me in back and show me what to look for. In return I'm going to record when I go through mine with the scope and put it on a DVD for him to use as an aid for his techs.

I'll admit I took this fairly lightly until he showed me a bad unit. Thanks for your input. I wouldn't have stopped if you hadn't posted this.


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