Partial "zoned" radiator installs

[SmileyDan]

Current situation:

• Oil fired boiler
• 24 hour programmer next to boiler
• Standard TRVs on 80% of rads - 22 in total
• No room thermostat
• Only half the rooms are heated (although with time more and more rooms are being heated - growing family)

Where I want to be:

• 7 day programmer
• Zoned TRVs that have independent timers and can call for heat
• No room thermostat unless I need one (if the TRVs aren't good enough)

The Evo Home solutions (Evohome, heat genius etc) are too expensive for us on a TRV basis, but is a partial install possible? My thoughts were:

• Zone the rooms that are currently heated, about 12 rads
• Turn TRVs on other rooms to '0'

This should give us similar benefits?

Do the install packages for these zoned solutions include installation of their TRVs where there is no TRV already (i.e. "proper" plumbing, draining of system etc)?

 

[kbdiy]

TRV's don't signal the boiler to demand heat, they only control local room temperatures (just). Fitting a room stat will give better control over heat demand and improve system efficiency.

 

[Phill Peck]

The Eco home does interlock the boiler

I think you can gave s partial system so all without the evohome revs would be part of one zone and then all with the Evo revs would each be their iwn zone

Dan Robinson will advise better he knows the evohome system well

 

[St0rmer66]

Evohome definitely does tell the boiler to fire on a room by room basis. But if you don't fit it to them all you will still need a way to control the other radiators (i.e. room thermostat/timer) and then at least one radiator as a by-pass unless you already have an automatic bypass valve on the system. You could use the existing timer for the 10 without and the Evohome for the rest I suppose, still with no room thermostat. I think you can get away with that since you already don't have one, if you had a thermostat already then taking it away would be making the system less efficient than it already is which wouldn't strictly be allowed (not that there's anyone who would do anything about it to be honest).

 

[SmileyDan]

Thanks guys.

But if you don't fit it to them all you will still need a way to control the other radiators (i.e. room thermostat/timer) and then at least one radiator as a by-pass unless you already have an automatic bypass valve on the system.

The bypass bit is where my plumbing knowledge ends (I don't have a lot of it).

Given we don't normally heat these rooms I figured leaving them on 0 would be ok - that way there is no extra heat used in those rads when the other TRVs are switching the boiler on.

But I have heard of this bypass concept, just don't understand it. The nearest rad, in a toilet, DOES have a TRV. There doesn't appear much rhyme or reason as to which ones do and which don't (actually many without TRVs are in rad covers which are also going... although some in rad covers DO have TRVs - my head).