I have a boiler (Crane HMT) that uses a Triple Aquastat relay 8124. I set the HI to 180 and when the thermometer calls for heat, it will go just over 200, releasing the relief valve throwing steam and water out. When i lowered he HI down to 140, it would fire up to 185 and stop burning, circ pump would run. I set the tstat to 15C and i woke up it was at 20C, I also heard the burner fire up ever 20 or so minutes going from 160ish up to little 180-190. Today i shut down the boiler and want the house to drop a bit in temperature to see if it calls for heat and when it stops. I disconnected the LO on the astat today aswell and see of that helps any. But if I set the HI to 180, shouldnt the burner quite when the temperature of the water reaches 180? Also, I am troubleshooting why the temperature was greater than what i set the tstat at as well. Also, the boiler was used to heat a small apartment building, would I have to change the nozzle to accomodate my 1400 sqft house?

I've had a Triangle Tube Prestige Excellence 110 combi (small internal DHW tank) running since March, 2009. The small DHW tank works fine for our empty-nest. I've been trying to eliminate a banging (water hammer?) in one of my three space heating zones pumped by the 110's internal pump. I'm not convinced it's water hammer - it may be due to poor installation of this zone's piping .... a lot of it is buried between a very old basement ceiling and a "newer" ceiling installed in the '70s. The noise only happens when this one zone is "on" and the 110 control switches to DHW heating priority - 20-to-30 seconds after either a shower or the wash machine starts. I hear the banging noise almost simultaneously with the internal valve stopping the space heating flow and opening the flow to the DHW tank. If two or more zones are "on", then it doesn't do it. I've talked with my installer (a very competent guy) and he had me verify that the expansion tank was plumbed in the right location (it was) and he had me check the expansion tank's air pressure (it was OK). So lately I've been tightening up the few locations where the piping in the noisy zone is exposed, but the noise is still there. In a Nov 12, 2010 posting (partial below) a forum member said there was a "special pressure relief tube that needs to be plumbed in". I'm wondering if this might be something that was missed in my installation. Can the member (or other readers) give me some detail on what that might be? Thanks in advance for any help you can give me. ============================================ Member jgalak wrote ..."No experience with the Excellence (just the Solo 110), but based on what the factory training taught about the Excellence, there are 2 issues you need to be aware of: 1) The DHW tank in the Excellence is very small. ..... 2) If you are zoning with circulators, there are no special issues. However, because of the way an internal valve works, if you zone with valves, there is a special pressure relief tube that needs to be plumbed in. If this is your situation, let me know, I'll post more details. Not sure if this issue is in the Excellence manual, but it's something they emphasized at the training (for good cause)."