Wireless / smart TRV's.....Are they worth it?

JohnPo

I think one of biggest issues is about understanding about how TRV's work and not those who are one this forum who actually take an interest.  Personally I am fed up going round in winter and telling folk off for opening a window 'cos they are hot' only for the TRV to ramp the heating up in that room.  Then going round and telling folk off for for changing the TRV to 'maximum' cos 'they were cold' some time / days later - just does my head in.

ManMadeWays

BUFF said:

Did you have existing TRVs where you have fitted the eTRVs? Did you already have a programmer/ room 'stat too? Was the Vaillant boiler existing or a new installation?
You have adjusted your  DHW & CH flow temps - how much of your hoped for 10,000 kWh annual saving do you expect that to account for?

It will be interesting to see if you get your hoped for saving (~35%). Please post your results achieved after a full year of use (when did you fit them?).

Yes we had TRVs before. Previously had a Drayton Digistat +3RF was ON 0600 to 0900 , 1530 to 2200. Existing boiler circa 8 years old. DHW down from 65 to 50 , CH from 75 to 60.

Change was made mid January, in the early days I was learning the settings and managed to have the heating on too much,as can be seen by consumption going up.

I can't work out how much is from eTRVs and how much is Temp changes. I do know that the amount of 'Radiator Hours' on each day is down 30% ie TV rooms are only heated in the evening, and bedrooms only come on at 2130/2200 rather than 1530, also in the morning they get an hour of heat rather than 3 hours, I mean you are up and dressed in 20 minutes ? .

I also got keen to open curtains when sunny and close when getting dark to trap heat.

The difference in use on a sunny day vs a cloudy day is large regardless of temperature.

Table below with some caveats, 2022 is monitored monthly, previous 3 years monthly averages are based on quarterly ? reads interpolated monthly by Scottish Power.

For this winter I have also insulated a historically very cold room, such that it was the coolset room over the summer heatwave so I'm expecting it to be warmest in winter !!

	Gas Kw/h
	3 year average	2022	Change
Jan	3,603.5	3,671.8	1.9%
Feb	3,151.8	2,297.6	-27.1%
Mar	2,788.0	2,044.8	-26.7%
Apr	2,069.3	1,704.0	-17.7%
May	1,781.5	659.6	-63.0%
Jun	1,025.1	550.0	-46.3%
Jul	615.4	548.4	-10.9%
Aug	874.3	358.2	-59.0%
Sep	1,372.7
Oct	2,125.4
Nov	2,857.6
Dec	3,513.3
	25,778.0

BUFF

Interesting, good that you have data. Although as you say it will be hard to quantify how much of the savings will be attributable to which change. & it's been a mild year - such that many peoples heating consumption dropped significantly.

ManMadeWays

Update end September

	Gas Kw/h
	3 year average	2022	Change
Jan	3,603.5	3,671.8	1.9%
Feb	3,151.8	2,297.6	-27.1%
Mar	2,788.0	2,044.8	-26.7%
Apr	2,069.3	1,704.0	-17.7%
May	1,781.5	659.6	-63.0%
Jun	1,025.1	550.0	-46.3%
Jul	615.4	548.4	-10.9%
Aug	874.3	358.2	-59.0%
Sep	1,372.7	418.0	-69.6%
Oct	2,125.4
Nov	2,857.6
Dec	3,513.3
	25,778.0
Feb-Sep	13,678.1	8,580.5	-37.3%

bordercars

In our local legion club the combi heating was installed in such a way ( luck than judgement ) that our engineer was able to install motorised valves and a stat in each of the members area and function hall which wouldnt be to dissimilar from and upstairs downstairs situation. As a friend of the RBL he only charged for parts and memory suggests the spend was sub £200.  2 x valves, 2 x isolators, 2 x room stats . 

[Deleted User]

The reason why eTRVs are not mandated for new builds is because the international jury is still out. I have been there and I invested over £1500 in Evohome smart heating with eTRVs. The savings were minor for the capital expenditure involved.

Fortunately, my buyer enthusiastically agreed my asking price on the spot. My ex neighbour told me me that he replaced the system with conventional controls a year later.

For each £50 you pay for an eTRV you have to make £50’s worth of savings.

In my present home, I have a Tado thermostat for convenience. It proudly told me in July that I had saved 100% on my heating but if I followed the advice below I could save a further 50%. My heating had been off for months.

ManMadeWays

Belated December update

	Gas Kw/h
	3 year average	2022	Change
Jan	3,603.5	3,671.8	1.9%
Feb	3,151.8	2,297.6	-27.1%
Mar	2,788.0	2,044.8	-26.7%
Apr	2,069.3	1,704.0	-17.7%
May	1,781.5	659.6	-63.0%
Jun	1,025.1	550.0	-46.3%
Jul	615.4	548.4	-10.9%
Aug	874.3	358.2	-59.0%
Sep	1,372.7	418.0	-69.6%
Oct	2,125.4	967.0	-54.5%
Nov	2,857.6	1,726.00	-39.6%
Dec	3,513.3	3,408.00	-3.0%
	25,778.0	18,353.3	-28.8%
Feb-Dec	22,174.5	14,681.5	-33.8%

December saving poor, but December was cold for a long while