Our Oil CH System has no thermostat

milliemonster

We bought our house almost 2 yrs ago now and it has Oil CH that has been installed about 7 years. I have never experienced oil CH before (always gas or solid fuel) but there is no thermostat to control it. So we either have to have the heating on or off and can only control the temp of the rooms by turning down the valves on the radiators (these are thermostat valves)

Is there any way of getting a thermostat fitted to somehow link into the system? The system has a timer which we program to come on and off twice during the day but once its on we can't control the temp of the rooms.

Any advice?

Splott_Boy

I think in your system you need at least 1 radiator without a TRV that will take the flow if all the other radiator valves close themselves ? Someone on here may know better.

My understanding was that the room temperatures should be set by your TRVs and you need to play about with the settings and a room thermometer to get them set up correctly.

We have TRV's (apart from on the bathroom radiator) and a thermostat in the hall. Advice seems to be that the TRV is left on max in the thermostat room otherwise the room never reaches a temperature to switch the main system off.

e.g. with the thermostat at 18 degrees c in the hall when that room reaches that temperature the system stops heating. Other rooms will be warmer or colder depending on a variety of factors (outside walls / windows / draughts) incuding the setting on the TRV you have selected.

Are you sure they are thermostatic radiator valves where you can vary the heat (rather than simply open or closed / on or off) ??

david29dpo

Very easy to fit a stat, better still bin the timer (or leave on constant) and get a programable stat.

Cardew

Many older systems had no room thermostat for gas and oil CH; albeit it is now mandatory.

The temperature of your rooms is controlled by the TRVs.

It is not necessary to have one radiator without a TRV(all mine have TRVs) if you have an automatic bypass valve(ABV)

Many people do not like wall thermostats as the siting is always a compromise - warm living room or cold hall.

I do have a wall stat, but I put it up to max(so it is always demanding heat) and control the room temperature by the TRVs.

david29dpo

Vert true but what stops the boiler cycling?

Cardew

david29dpo wrote: »

Vert true but what stops the boiler cycling?

Nothing! - Well other than when the water in the system is up to temperature.

Indeed it is the downside of the method I use, but for me it is the lesser of 2 evils. As said many times, the siting of a room stat is always a compromise.

Have the stat in a living room and that determines how CH operates in the rest of the house. For instance I might want to use that room but have heating in other rooms(including bedrooms). With no TRV on the living room radiator, I have to turn up the thermostat above what is required to get the CH to operate in other rooms.

Have the stat in a cool hall(like mine) and I have to heat that hall or juggle with the thermostat setting.

My pump is constantly running when CH is on, but they use little power and has needed replacement once in 21 years. The boiler has had 1 thermocouple in the same period.

I am not saying 'my method' is best, but merely pointing out that having no room stat isn't a problem; and I have read plumbers forums where participants adopt the same method as I do for their own heating.

david29dpo

Thanks, I have wireless Prog stat which i am forever moving around trying to find the best place!

milliemonster

Thanks for all your replies, sorry we do have a programmable timer, its not just a timer that is either on or off, actually I don't think the radiator valves are thermostatically controlled, I think they are just valves with numbers on where you can turn them up or down, we have a fairly small living room and no matter how hot it gets, the radiator never switches off unless we manually turn it off.

So I guess I should be looking at proper thermostatic control valves for the radiators, do you put these on every one in the house?

Cardew

milliemonster wrote: »

Thanks for all your replies, sorry we do have a programmable timer, its not just a timer that is either on or off, actually I don't think the radiator valves are thermostatically controlled, I think they are just valves with numbers on where you can turn them up or down, we have a fairly small living room and no matter how hot it gets, the radiator never switches off unless we manually turn it off.

So I guess I should be looking at proper thermostatic control valves for the radiators, do you put these on every one in the house?

Those are TRVs (Thermostatic Radiator Valves) if like these.

http://www.inspiredheating.co.uk/acatalog/THERMOSTATIC_RADIATOR_VALVES_TRVs.html

milliemonster

Yes they look like those!, so how come they never turn off then? maybe the insulation in our house needs looking at if the house is never getting warm enough!

Cardew

milliemonster wrote: »

Yes they look like those!, so how come they never turn off then? maybe the insulation in our house needs looking at if the house is never getting warm enough!

It could be that the 'plunger' is stuck.

If you unscrew the top of the TRV( turning the the knurled nut) - don't worry no water will come out - you will see a thin pin, this is spring loaded and needs to be pushed down a few times to exercise it.