Aquastat replacement, DYI or call a professional?


Old 02-13-16, 11:25 PM
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Question Aquastat replacement, DYI or call a professional?

Today might be the coldest day of the year (New England winter finally is here), perfect timing for heating issues.

I have no problem with fixing electrical issues but my boiler is so old (gas fired, from ~1960) that makes me nervous. Could someone answer yes or no (details are of course welcome) to the questions below?

1. There is no sense in trying to repair the circulator relay, correct? That is the broken part and a pin seems to have gotten loose or broken. When the aquastat tries to engage the circulator it fails. If I push the relay first then it works until the next time. Name:  IMG_0074.jpg
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2. Can a L8124E1016 be used? The aquastat is a L8024F mounted horizontally. The replacement part seems to be L8124E. The pictures online seem to say that L8124E1016 is vertical.

3. Do I need thermal paste?

4. Should I nuke the whole boiler from orbit?
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The last one is is rather drastic and not feasible since I don't have any nukes and spaceships. Nevertheless thank you for reading
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Old 02-14-16, 06:20 AM
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Not really that difficult to replace, looks like you have the room to mount it vertically,follow the mfg. about the thermal paste, have fun.
Old 02-14-16, 07:40 AM
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You might be able to easily fix it. Could be nothing more then a cold solder joint. It might be worth your wild to disassemble it and see if you can re-solder the loose pin.
Old 02-14-16, 08:53 AM
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Look at Table 1 on page 3; it says the L8124E can be mounted vertically or horizontally.
Old 02-14-16, 10:07 AM
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I was able to fix it in the short-term so now I have time to find a deal for a replacement/spare aquastat.

Based on the feedback of tomf63 and Geochurchi (thank you guys!) I decided to poke deeper. I was able to take apart the relay without moving the whole aquastat and it seems the pin is a simple fastener to keep the spring under tension. The other end had broken after few decades of work (the small ring in the pictures).

I took it apart, cleaned well with alcohol, used fine sand paper for the contacts and then hammered the fastener back to keep the parts from making proper contact. So far so good, keeping fingers crossed.

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Thank you zoesdad too, I looked at the 8124E specs before but I had missed the mounting description.

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