Very interesting indeed....:
I have just completed the re-binding steps and gone through some crude tests given limited time between work ;-)
Observations:
I guess this is how I was expecting the R8810 OT Bridge to function with Evohome: only fire up at a high flow temp when there is a significant difference in room temp vs desired set point.
What I am seeing with R8810 OT Bridge with Evohome is more like on/off, i.e. on=max CH flow temp, and off = off or very very low CH flow temp. This has somewhat surprised me. But maybe that is expected behavior, and the HR92 devices I have need time to learn to request lower than 100% heat demand? After all, mine have been messed up for the last week or so with intermittent boiler firing every 20-30mins.
Does anyone else have an R8810 OT Bridge with a T87RF OT compatible Honeywell round stat that can try this as well?
I have just completed the re-binding steps and gone through some crude tests given limited time between work ;-)
Observations:
- Boiler reacts very very swiftly to changes made via the T87RF round thermostat (up or down) which in turn goes through the R8810 OT Bridge. No delays (obviously) due to HR92 comms and Evohome aggregation.
- Different behavior to Evohome is noted when an increase of only 0.5 degrees above setpoint is made when the room is reporting to be at the original setpoint. (i.e. a 0.5 degree increase request in room temp). The T87RF requested around ~44 degrees (well that is what the LCD boiler temp was showing to be fair). Evohome seems to send through a max CH flow temp for even 0.5 degree room temp increases (via HR92 sending what I can only presume to be a 100% heat demand to Evohome even for 0.5 degrees)
- Boiler temp was held at approx ~65 degrees for a 1.5 degree increase request in room temp and reduced as it approached the set point
- Only when I pushed beyond 2.5 degree increase did the boiler start to really fire up at full pelt. I didn't have time to see it heat up to a max temp and then stop (whatever that was) unfortunately - i only saw it get to 72 degrees and it was still going before I re-binded it all back to how it was setup with Evohome, but appeared to be similar boiler firing to Evohome when any temp changes are requested
- Bonus bullet: the T87RF round thermostat displayed boiler firing symbol when directly connected to R8810 OT Bridge and when heat was requested :-)
I guess this is how I was expecting the R8810 OT Bridge to function with Evohome: only fire up at a high flow temp when there is a significant difference in room temp vs desired set point.
What I am seeing with R8810 OT Bridge with Evohome is more like on/off, i.e. on=max CH flow temp, and off = off or very very low CH flow temp. This has somewhat surprised me. But maybe that is expected behavior, and the HR92 devices I have need time to learn to request lower than 100% heat demand? After all, mine have been messed up for the last week or so with intermittent boiler firing every 20-30mins.
Does anyone else have an R8810 OT Bridge with a T87RF OT compatible Honeywell round stat that can try this as well?
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