Need help in diagnosing TT Prestige Excellence 110 "low" heat issue.
Full system installed ~ 6 years ago, no issues until now. Two boilers installed for identical apartments, so I can also compare to what the "OK" boiler is doing for outputs.
Installation: Propane fuel, 4 cast iron radiators plus 1 kickspace heater, each on own loop. Pex supply/return lines. 1 internal and 1 external circ pump. 2 expansion tanks (1 heat (on return), 1 DHW).
Thermostat set at 74F, actual room temp 62. Set it to 80, and still doesn't get up to temp (got up to 70, but the CH target still 132).
Here's the "INFO" (these are avg/range, I tracked for awhile):
1 (measured supply H20) 128-134
2 (Mea RTN H20) 124-130
3 (Mea DHW) 160(mostly), 154,152
4 (Outdoor) 30-26
5 (Flue temp) 126 (max)
6 (Target supply temp) 132 (never changed except during Hi Fire Test Mode)
The other boiler fires off and circulates 174F water for heat. This is what I would expect.
I've replaced the Honeywell R845A switching relay with a Taco SRT501 (originally thought that was the issue- but not).
I shut off the DHW, to eliminate the priority of hot water, to see if the DHW temp probe was the issue, but it still didn't come up to temp.
I can tell the external circ pump is running, as I can feel a slight vibration with hand on top, and the manifolds get hot.
Ran it in Hi Fire Test Mode (stat at 80), it cycled through, the same as the "OK" boiler (stat at 65). It put the CH target to 150F, and the CH water would get to 158F. After running the Hi Fire Test Mode, with the thermostat set to 64, the switching relay no longer indicated a call for heat. - But it seems to be calling for heat otherwise.
I checked the thermostat resistance (honeywell classic round with mercury), and it works.
Cleaned out the condensate traps on both boilers while I was at it. No red herrings there, and no improvement.
The Parameter settings are the same as the "OK" boiler. I have it set to max target supply temp of 150F. I sized the radiators for the lower supply temps, so larger than "typical" rads.
Any suggestions as to what it may be, or what I should check next? The issue seems to be the Target Supply Temp setting doesn't match the heat call.
Thanks for any and all help. HeatingHelp has improved my knowledge depth in Mod/Cons, hydronic and steam heat tremendously over the last 6 years.
Full system installed ~ 6 years ago, no issues until now. Two boilers installed for identical apartments, so I can also compare to what the "OK" boiler is doing for outputs.
Installation: Propane fuel, 4 cast iron radiators plus 1 kickspace heater, each on own loop. Pex supply/return lines. 1 internal and 1 external circ pump. 2 expansion tanks (1 heat (on return), 1 DHW).
Thermostat set at 74F, actual room temp 62. Set it to 80, and still doesn't get up to temp (got up to 70, but the CH target still 132).
Here's the "INFO" (these are avg/range, I tracked for awhile):
1 (measured supply H20) 128-134
2 (Mea RTN H20) 124-130
3 (Mea DHW) 160(mostly), 154,152
4 (Outdoor) 30-26
5 (Flue temp) 126 (max)
6 (Target supply temp) 132 (never changed except during Hi Fire Test Mode)
The other boiler fires off and circulates 174F water for heat. This is what I would expect.
I've replaced the Honeywell R845A switching relay with a Taco SRT501 (originally thought that was the issue- but not).
I shut off the DHW, to eliminate the priority of hot water, to see if the DHW temp probe was the issue, but it still didn't come up to temp.
I can tell the external circ pump is running, as I can feel a slight vibration with hand on top, and the manifolds get hot.
Ran it in Hi Fire Test Mode (stat at 80), it cycled through, the same as the "OK" boiler (stat at 65). It put the CH target to 150F, and the CH water would get to 158F. After running the Hi Fire Test Mode, with the thermostat set to 64, the switching relay no longer indicated a call for heat. - But it seems to be calling for heat otherwise.
I checked the thermostat resistance (honeywell classic round with mercury), and it works.
Cleaned out the condensate traps on both boilers while I was at it. No red herrings there, and no improvement.
The Parameter settings are the same as the "OK" boiler. I have it set to max target supply temp of 150F. I sized the radiators for the lower supply temps, so larger than "typical" rads.
Any suggestions as to what it may be, or what I should check next? The issue seems to be the Target Supply Temp setting doesn't match the heat call.
Thanks for any and all help. HeatingHelp has improved my knowledge depth in Mod/Cons, hydronic and steam heat tremendously over the last 6 years.