Honeywell AQ252 Mixing Control Temperature Algorythm

vvzz

Hi Everyone,
I have recently removed a whole bunch of baseboards in my house and replaced them with cast-iron radiators. I have a fairly new dunkirk CI boiler. My goal is to have a full ODR, so I got the Honeywell AQ252 mixing reset control. Mostly because I was able to snag a brand new one on ebay for $200. I also got the matching AQ1000 communicating thermostat. I'm using injection pump to control mixing into the radiator loop. Overall, the whole system seems to be operating very well - no ghost flows, the system loop is correct temperature.
However, the control's algorythm is a little bit confusing and Honeywell's manual doesn't go into any detail about it. Here is the problem. Since I'm running full ODR, I expect my system to be in almost constant circulation. It would work well, since all radiators match the heat loss pretty closely and are also outfitted with TRVs to deal with any irregularities. So I set the thermostat to a slightly higher temperature, hoping that it will never get satisfied and run the system in constant circulation. But what happens is that AQ252 control seems to start raising target mix temperature after a while higher and higher. Its about 45 degrees outside, and it starts up with something like 95 degree water(which seems appropriate for this temp), but then it raises it to like 120. To be clear - It doesn't raise on its own, the control increases the temperature and increases injection pump speed. Of course, I do not want that, as it kind of defeats the whole point of the ODR.
My theory is that the control 'sees' that the room temperature is not satisfied with given water t and it tries to compensate for that. Does this sound plausible? Does anyone have experience with honeywell controls and can confirm this?
If so, how do I rectify this as I just want to circulate water all the time. Should I just jump the thermostat terminals and let the ODR and TRVs handle everything?

(Sorry for messy wiring in the pictures, I was too eager to see the system in action and didn't properly route them yet)

Zman

That is a tough one. Ordinarily what you are experiencing is called "Boost" or "Parallel shift". It can be disabled in the setup menu as it is undesirable for your configuration. I agree, it is not addressed in the manual. I think a call to tech support may be in order.
Carl

vvzz

I'm really not looking forward calling honeywell. I'm imagining there will be long wait times and a whole bunch of people who have no clue about this particular control

Anyhow, I jumped the TT terminals and so far it seems to actually perform as I want it to. It has been about two hours and the mix temperature is staying constant. I was a little bit excited about having thermostat display outdoor T, but oh well.