HONEYWELL L7224U ELECTRONIC AQUASTAT

Hi all,

Has anyone used the Honeywell L7224U electronic aquastat on an oil fired boiler yet ??? In the past 6 years, I have had to replace 3 L8148A control boxes. The circulator relays keep going bad. It is not the relay contacts, but rather the relay coil fails to hold the relay in the energized position after the box heats up, and then it starts to chatter. I replace the box, and then it's good for another year or two. It's working OK now, but just in case it fails again, I got an electronic box--the L7224U.

This box has both high & selectable low limit controls--low limit can be turned on or off. Everything is microprocessor controlled, and there is a digital display. All functions are electronically adjustable via 2 buttons. Are these boxes any more reliable than their predecessors ??? If there is a power interruption, does the box lose all of its' settings and have to be reprogrammed again ??? I see what appears to be 3 miniature relays on the circuit board. Are these more reliable than the old style larger ones ??? This box comes with a temperature probe for the boiler well that has a cable and a sensor at the end of the cable. It comes with heat transfer compound--how much do you use ???

RON ======================================================== Remove the ZZZ from my E-mail address to send me E-mail.

Reply to
Ron in NY
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I just saw one of those. It came with a Buderus boiler as part of the package, but we were installing the "logamatic" control instead. My personal opinion: Go with the more conventional mechanical box, at least at this point, you don't want to be the Guinea Pig. In your situation, since its only the circulator relay that isn't working, I'd leave the existing aquastat relay in place and get a Honeywell R845 relay to control the circulator and if you need it to also start a "cold start" boiler, (if you aquastat relay doesn't have a low temp cut in) it has auxiliary contacts for that purpose

Reply to
RBM

Ron in NY posted for all of us...

I'm not in the business but would the relay be failing because the circulator is drawing too much?

Reply to
Tekkie®

The L8148A is prone to bad solder joints where the relay solders to the board. They used a small flexible pin in a big hole, solder rings are on both sides but they didn't use a plated through-hole. Cheap, cheap, cheap. Repairable if you want to take the time to pull the board from the box and have at it with a soldering iron.

Dave

Reply to
spamTHISbrp

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