buderus bfu sensor

md

i have used several g115 boilers and have had good luck with them,,, i never got to try a bfu indoor sensor, all my set ups are just with logamatic and outdoor sensor, i have a small home 36x28 all 1 floor, main room is 18x28  3 zones in home total, i read not to use the bfu sensor on multi zone designs,,, i want to use bfu in main room,, second zone is 3 small bedrooms and last zone is a small enclosed porch/ mud room,it has 3 cold walls and cold floor.in mud room.,, any thoughts,,, thanks,,

Mark Eatherton

Big Friggin Unit...

I have deployed the BFU in a similar, multi zone scenario. What is critical, is that the zone chosen for the placement of the BFU must be the worst case heat loss scenario zone (porch?). Otherwise, the high loss zones will not heat correctly because the BFU is seeing internal core zone satisfaction.



In one large home we did with all non electric thermostats, we put the BFU in a room that had a high heat loss. Their (Buderi) recommendation is to NOT have any kind of zone control on the BFU's "reference" zone, making it a constant flow zone. We put the pressure activated bypass on the supply line serving the reference zone. This way, if numerous other zones were calling for flow, the PAB would not allow a lot of flow through the reference zone until which time the other zones were satisfied.



Worked like a champ, but I would HATE to be a first year service technician attempting to trouble shoot the system. We left a fairly descriptive set of operating instructions, but who ever reads those....



ME