Hi,
I'm thinking about jumping ship from Hive and want to learn a little more about Evohome before making the leap. My main complaint with the Hive smart TRV is that when a schedule calls for a setpoint change, climbing to say 20°C in a room measuring 15°C, it only opens the valve in tiny baby steps with 5 minute gaps that takes 30 - 40 minutes to allow any heat through.
Can anyone tell me how the EvoHome schedule and the HR92 behave in the same circumstance described above?
The other question I have is does Evohome require HR92 valves on every radiator? I only really want the HR92s for 4 rooms with the rest grouped as one zone with multiple radiators still fitted with traditional TRVs. Can Evohome accommodate that?
P.S. do the HR92 batteries really last 2 years?
Thanks in advance!
Phil
HR92 - So how does it work?
Re: HR92 - So how does it work?
I'm only a user of EVOHome but will try to answer as much as I can.
My valves open widely when required and then close down as the temperature gets closer - I've not noticed an issue with delayed heating up or overheating due to valves not closing down again.
I only have HR92 valves on 5 radiators, the rest work without. The EVOHome main unit has a thermostat but must be associated with a HR92 so in my case I rely on the dumb rooms (old TRVs) getting enough heat when any of my 5 rooms generate demand, but you can also have a HR92 left in a somewhere, paired but not mounted, to generate demand in the area with old TRVs.
Only had my system 6 months but no batteries needed replacing yet.
My valves open widely when required and then close down as the temperature gets closer - I've not noticed an issue with delayed heating up or overheating due to valves not closing down again.
I only have HR92 valves on 5 radiators, the rest work without. The EVOHome main unit has a thermostat but must be associated with a HR92 so in my case I rely on the dumb rooms (old TRVs) getting enough heat when any of my 5 rooms generate demand, but you can also have a HR92 left in a somewhere, paired but not mounted, to generate demand in the area with old TRVs.
Only had my system 6 months but no batteries needed replacing yet.
Re: HR92 - So how does it work?
As Brummy said - the valves open fully wide if there is much of a difference between the current temperature and the set point, they then gradually close in stages as the set point is reached - it works really well.
Because most of the power goes to running the valve motor, how long the batteries last depends of course on how many cooling down and heating up cycles you have, but in my experience the batteries do last around two years in less used rooms with fewer switchings, and maybe 15-18 months in the two rooms that do the most heating up and cooling down. You also get quite a few days between when the controller warns you of a low battery and when it will actually stop working.
That's using decent alkaline batteries of course.
Because most of the power goes to running the valve motor, how long the batteries last depends of course on how many cooling down and heating up cycles you have, but in my experience the batteries do last around two years in less used rooms with fewer switchings, and maybe 15-18 months in the two rooms that do the most heating up and cooling down. You also get quite a few days between when the controller warns you of a low battery and when it will actually stop working.
That's using decent alkaline batteries of course.
Re: HR92 - So how does it work?
I'll third the comments about the HR92's opening fully when the demand is made for heat then gradually closing down as the room warms up thus preventing over running the heating. As an example our bedroom is set to 19C from 07:30, the valves open up at around 06:30 to start the warming process and are basically fully closed again by 07:30 and the room is at temperature as I kick my feet from under the duvet. During the hour or so the room is to remain at 19C the valve whirrs occasionally and lets a little bit of hot water in as required but by 08:30 the valve is fully closed again and the heat allowed to drop back to background (17C).
The HR92 is a clever wee beastie compared to it's extremely thick cousin the standard TRV and I have to say I have been very impressed by the entire EvoHome system. It's saved me about 30% on my oil bill a year thanks to the precision temperature control and the numerous programming options for the 12 zones in my house.
As for batteries, I'd say 18 months is more realistic than 24 but that does depend on how much the valves have to work. Once 1 sensor shows a low battery be prepared to run round with a big pack of AA's and replace them all with in a week or 2
The HR92 is a clever wee beastie compared to it's extremely thick cousin the standard TRV and I have to say I have been very impressed by the entire EvoHome system. It's saved me about 30% on my oil bill a year thanks to the precision temperature control and the numerous programming options for the 12 zones in my house.
As for batteries, I'd say 18 months is more realistic than 24 but that does depend on how much the valves have to work. Once 1 sensor shows a low battery be prepared to run round with a big pack of AA's and replace them all with in a week or 2