Oil boiler / TRV use

carkk2023

Hi all,

we moved into a new house last August, and I’ve found boards to be so so useful over the past few months. I’ve found a lot of answers re heating, but not exactly what I’m looking for.

our set up is a firebird popular 120 boiler, with around 17 rads, however some of them quite small in cupboards etc. All are fitted with TRVs. There are no electronic thermostats, and it’s split into 3 zones using a horstmann xl clock, with the ‘water’ zone being used as the upstairs heating zone. This clock has a max of 3 ‘on’ periods per day. We don’t use upstairs at all, and heating is off, so only really 10 rads being used.

Ive been experimenting, but am ultimately very new to TRV use. My understanding from other posts is that it’s not good for the boiler to be turned on, but not doing much work. Is it better to have all TRV valves set to 2 or 3, and the boiler on for long periods of time and kept at a steady temperature, or is it better to have it coming on for an hour or two here and there… both for oil use and boiler longevity…

as in, is there a downside to having the boiler on all night for downstairs bedroom only zone (3 rads), with TRVs set to mark 2 or 3, so not over 20 degrees… with no electronic thermostat the boiler won’t turn off as such, I don’t think? Or how should they (TRVs) be used

house is 20 years old and well insulated.

any advice on how to most efficiently use current system would be appreciated!

windowcills

Trvs set mamimum temperature per room, they only last about 15 years so might need to be replaced, half of mine are stuck

You need a stat or 2 to set min temperature (and max too), min temperature can be set lower when the house is empty

If its a condensing boiler set the boiler to the lowest temp and the pump to 3, make sure pipes to boiler are insulated if outdoors

deandean

In the last 2 years I helped my parents upgrade to a condensing boiler, and fit TRVs, in a 30yo house with OFCH.

There has been no significant reduction in oil use.

They want a house where its 23deg C or so all the time, and for that you gotta pay the price for the fuel.

In my house its never more than 17-18degC, and we're used to it. The heating bill is < half that of my parents.

Best wishes 😊

John.G

I have a oil fired SE (non condensing) oil fired 20kw Firebird in my 51 year old 4 bed detached house, all rads TRVd except for two in a combined dining/living room where we spend most of the time, I have a digital roomstat that gives very precise control (to within 0.2C of the SP temperature) located in the combined rooms, heating on 16/18 hrs per day, SP temperature 19.5C until around 1800 hrs, then increased to 20.5C for the remaining 7 hrs or so, due to the south facing rooms the boiler is often off for hours before re heating required, kitchen TRV set to give 18C, works very well as it shuts the rad off once any cooking, b/room TRVs set to 16/17C. System works quite well as I have the two non TRVd rads throttled so that even though the boiler run time is controlled by the combined rooms stat, the whole house is quite reasonably comfortable. I've (4 year) averaged 1480 ltrs/year, say 15200kwh of Kerosene.