I believe my boiler is short cycling in my new home.
Here are some details.
1550sqft ranch house with walk out basement.
Radiant Tube in the basement slab.
Hot water coil mounted in duct work for main floor.
Indirect water heater.
HTP UFT-80W Boiler
No Outdoor reset.
The floor was wired to the CH terminals on the boiler and ran at a set temp of 100* F
The Hot Water coil and DHW were wired to a 2 Zone Taco Pump Control and ran at a set temp of 170*F
When the infloor would call for heat the boiler would run for a good amount of time 30+min
When the Hot water coil would call for heat the the boiler and fan would run for a short period of time, less than 10 minutes.
[URL=http://s61.photobucket.com/user/coryrood/media/Boiler_zps8sqksrva.jpg.html][IMG]http://i61.photobucket.com/albums/h72/coryrood/Boiler_zps8sqksrva.jpg[/IMG][/URL]
I started doing a bunch of research and thought i found the solution for my problem, I needed to lower the hot water coil water temp. Problem was that the boiler could only have two temps. DHW and CH. Since I don't want to change the DHW temp I needed to get the HWC on the CH circuit. But 100* wouldn't be hot enough for the HWC. I decided to install the outdoor sensor and enable reset. with the hottest water on the outdoor reset curve expected to be around ~140* I decided that I needed to install a TMV on the infloor. This is where I'm at today.
The slab and HWC are now on the Taco controler which is on the CH circuit of the boiler set with Outdoor reset.
The DHW is on the DHW circuit of the boiler and set to 170*F
boiler run times have not really increased with the HWC even with water temps as low as 110*F
boiler run times for the infloor have tanked though now. The boiler heats until the supply reaches a temp slightly above it's set point and then shuts down only to refire shortly there after because the infloor is still calling for heat and returning the 'cold' water and cooling the boiler below the set point. Why isn't the boiler modulating to maintain it's set point?
Thought I had my head wrapped around how this system should work but I seem to have made things worse.
Here are some details.
1550sqft ranch house with walk out basement.
Radiant Tube in the basement slab.
Hot water coil mounted in duct work for main floor.
Indirect water heater.
HTP UFT-80W Boiler
No Outdoor reset.
The floor was wired to the CH terminals on the boiler and ran at a set temp of 100* F
The Hot Water coil and DHW were wired to a 2 Zone Taco Pump Control and ran at a set temp of 170*F
When the infloor would call for heat the boiler would run for a good amount of time 30+min
When the Hot water coil would call for heat the the boiler and fan would run for a short period of time, less than 10 minutes.
[URL=http://s61.photobucket.com/user/coryrood/media/Boiler_zps8sqksrva.jpg.html][IMG]http://i61.photobucket.com/albums/h72/coryrood/Boiler_zps8sqksrva.jpg[/IMG][/URL]
I started doing a bunch of research and thought i found the solution for my problem, I needed to lower the hot water coil water temp. Problem was that the boiler could only have two temps. DHW and CH. Since I don't want to change the DHW temp I needed to get the HWC on the CH circuit. But 100* wouldn't be hot enough for the HWC. I decided to install the outdoor sensor and enable reset. with the hottest water on the outdoor reset curve expected to be around ~140* I decided that I needed to install a TMV on the infloor. This is where I'm at today.
The slab and HWC are now on the Taco controler which is on the CH circuit of the boiler set with Outdoor reset.
The DHW is on the DHW circuit of the boiler and set to 170*F
boiler run times have not really increased with the HWC even with water temps as low as 110*F
boiler run times for the infloor have tanked though now. The boiler heats until the supply reaches a temp slightly above it's set point and then shuts down only to refire shortly there after because the infloor is still calling for heat and returning the 'cold' water and cooling the boiler below the set point. Why isn't the boiler modulating to maintain it's set point?
Thought I had my head wrapped around how this system should work but I seem to have made things worse.
