Replies

1. 
   NickNukeEm | Dec 12, 2004 02:08am | #1

   Your relay coil is going bad, if not there already.  I just had this happen and had to replace the honeywell aquastat controller.  (I got the relay to remain energized when called for by jamming a wedge between the boiler and control box, for some reason flexing the box a certain way causes the relay to work.  This has worked so well, in fact, I still haven't replaced the aquastat, which is in a box in the shop.  Too lazy; if it works, why screw with it.)

   The tough part will be finding a replacement, exact or one that's compatible.  See if you can find the model number of the controller, it may require a flashlight and mirror, if it's there at all.  Then go to partsguy.com and you might be able to find one there.  They had a compatible replacement for mine, but it cost $250, so don't faint at the price.  Check on ebay first, search under Honeywell and aquastat.

   I don't know what your setup is, mine has a dry well for the sensor.  That means a brass well is screwed into the boiler and the sensor that is attached to the aquastat slips into the well, so no draining is required to replace.  If you have a wet well, you have the unfortunate task of draining the system to replace the well.  Draining isn't bad, it's the refill and venting that's time consuming.

   Incidently, both my old and the new aquastat controllers were designed to be mounted either horizontally, or vertically.  I'm not sure about yours, obviously, but I don't think position really matters.

   Good luck.

    

    

   I never met a tool I didn't like!
1. 
   mccarthitect | Dec 13, 2004 07:22pm | #2

   Thank you very much.  You've confirmed what I suspected the problem was, I just wasn't sure (not having worked on a boiler or boiler controller before) if I could replace just the relay or if the whole box had to be replaced.

   I frankly don't know what kind odf sensor I've got, but I have the original documentation and it's a small house, so the draining/refilling and reventing doesn't take a enormous amount of time.

   I'll let you know how it goes if/when I find replacement.

2. 
   PaulBinCT | Dec 13, 2004 09:01pm | #3

   If the relay sparks, it's very possible that the coil is fine (that it is pulling the contacts closed) but that the points are dirty or pitted. IF you think you are OK with this try the following. Turn off the power to the controller. If you can unplug the relay, do so, being sure that there is a keyway so it can only go in one way, or mark it, if it isn't removable just be very sure all power is off before proceeding.  Open the plastic housing if there is one, often with two small screws at the bottom of the case (some relays have cases that you pry off with a small screwdriver tip).  Once it's open, very carefully remove the small spring that holds the relay leaves in the nonenergized position.  You should now have the relay contacts exposed.  Clean all of them, (both sides of the leaves, as well as all faces of the fixed points, with very fine emery cloth or similar, reassemble and check it out... Otherwise the relay may well be marked with a make and model and it may be very easy to replace the relay alone.

1. 
   mccarthitect | Dec 20, 2004 09:06pm | #4

   Thanks for the suggestion.  I opted to just jump the relay and have the circulating pump run continuously.  It's made for that option, I extract the most heat possible, and I'll just disconnect it at the end of the heating season.

1. 
   PaulBinCT | Dec 20, 2004 09:09pm | #5

   Glad it worked, always nice to make the right guess ;)

2. 
   ClaysWorld | Dec 20, 2004 11:04pm | #6

   Time is on your side while it's working --But I would look at getting it back to the original configuration, ie get the parts. Or start pricing the pumps.

1. 
   mccarthitect | Dec 20, 2004 11:56pm | #7

   It's a new pump.  I plan to get the controller back to the original configuration next spring - on my schedule rather than the boiler's.

1. 
   PaulBinCT | Dec 20, 2004 11:59pm | #8

   Didn't occur to me but Clay's point is well taken.  It's possible that the pump isn't rated for continuous duty.  If not, and if you fry it, it's sure gonna cost more than a 5 dollar relay.  If you need help spec'ing out a replacement relay, let me know...

2. 
   mccarthitect | Dec 21, 2004 01:27am | #9

   The pump is rated for continuous duty.