I've been looking at Evohome for sometime and came very near to purchasing earlier this year before I got cold feet around my current setup. The recently announced evohome security system has got my interest going again, but I'm still concerned that it would be right for me.
I currently have a two-zone heating system with a combi boiler, two wireless heatmiser thermostats, and two two-port valves control the heating in an S-Plan configuration. One zone is a single (large) UFH room the other zone is for the rest of the house fitted with radiators (and the thermostat mounted in the hall). The majority of radiators are fitted with TRV's except two towel rails in the two bathrooms. There is also no ABV currently fitted, the boiler is around 12 years old and does not support opentherm.
Two things originally put me off evohome, and I'd appreciate your views on these:
The first ... My current setup has real issues controlling the UFH temperature. It takes at least a couple of hours to warm up the room from cold, and also can overrun excessively i.e the room temperature will keep rising after the thermostat has reached the set temperature and turned the boiler off - the result is that the room can become uncomfortably hot.
I was originally attracted to evohome due to the optimize start feature, as it would be able to work out to start heating a couple of hours before we are up in the morning, and know to cut the heat before it reaches the set temperature so the room doesn't become too hot. However, I read somewhere (I thought it was on this forum, but can't find the thread now) that the optimize start is not suitable for UFH due to the large offsets required. Is that correct, or am I getting concerned over nothing?
The second ... I understand that evohome won't be able to drive both the radiator valves (HR92UK) as well as the second two-port valve for the radiator zone. So I'd need to fix the second two-port valve to be always open. Not a problem as the TRV's will stop heated water flowing through the radiators when only the UFH is calling for heat ... except for the two towel rails that I can't fit TRV's to (the current pipework does not allow TRV's to be fitted). Maybe this isn't a concern as it provides a bypass loop (no ABV required?), and means the towel rails will likely always be warm ... however I am concerned about the inefficiency of the system as one towel rail in particular is on a very long pipe run from the boiler. Is this a justified concern, or will the gains with evohome far out way the inefficiency here?
Don
I currently have a two-zone heating system with a combi boiler, two wireless heatmiser thermostats, and two two-port valves control the heating in an S-Plan configuration. One zone is a single (large) UFH room the other zone is for the rest of the house fitted with radiators (and the thermostat mounted in the hall). The majority of radiators are fitted with TRV's except two towel rails in the two bathrooms. There is also no ABV currently fitted, the boiler is around 12 years old and does not support opentherm.
Two things originally put me off evohome, and I'd appreciate your views on these:
The first ... My current setup has real issues controlling the UFH temperature. It takes at least a couple of hours to warm up the room from cold, and also can overrun excessively i.e the room temperature will keep rising after the thermostat has reached the set temperature and turned the boiler off - the result is that the room can become uncomfortably hot.
I was originally attracted to evohome due to the optimize start feature, as it would be able to work out to start heating a couple of hours before we are up in the morning, and know to cut the heat before it reaches the set temperature so the room doesn't become too hot. However, I read somewhere (I thought it was on this forum, but can't find the thread now) that the optimize start is not suitable for UFH due to the large offsets required. Is that correct, or am I getting concerned over nothing?
The second ... I understand that evohome won't be able to drive both the radiator valves (HR92UK) as well as the second two-port valve for the radiator zone. So I'd need to fix the second two-port valve to be always open. Not a problem as the TRV's will stop heated water flowing through the radiators when only the UFH is calling for heat ... except for the two towel rails that I can't fit TRV's to (the current pipework does not allow TRV's to be fitted). Maybe this isn't a concern as it provides a bypass loop (no ABV required?), and means the towel rails will likely always be warm ... however I am concerned about the inefficiency of the system as one towel rail in particular is on a very long pipe run from the boiler. Is this a justified concern, or will the gains with evohome far out way the inefficiency here?
Don