How long should you run the heating for?

kmb500

Hi, we started using our heating a few weeks ago and I am very conscious of the cost of running the heating. I'm not sure what a normal usage of heating is. We only need the house warm in the evenings as both me and my housemate go to work during the day. It feels like the house gets quite cold once the heating stops running, and also the heating takes a long time to warm up.

Today I have run the heating for 3 hours. Thermostat is set to 21. Started at 12 degrees; at 1 hour it was at 17. At 2 hours it was at 19. It's just reached 3 hours (so now turned off) and it's at 20.

Is this normal? I dont even know how much more time it would take to reach the target temperature. I would have thought it should be able to reach 21 in 3 hours but maybe my expectation is not realistic.

Most of the radiators seem to work, at least they feel hot. (except 2 which aren't warm)

BikingBud

12deg seems cold considering it is still very mild outside, how are you measuring this?

Are you aiming for 21 deg throughout the house or comfort? Are they the same thing?

Where is the thermostat and where are you spending most of the time?

What powers your heating?

Do all rooms have rads, what are the TRVs set at?

Having a rad adjacent to a stat with a TRV set high may shut off the heating before other rooms get chance to warm up,.

Where are the 2 that are not warm?

BUFF

really need more info to give you an informed opinion (but every house will be different). e.g.

How old is the house & how well insulated is it?
Boiler make & model? What flow temperature is it running?
Do you have TRVs on your radiators? If so what make & what are they set to?

tacpot12

The time to heat the house up will depend a range of factors, but three hours to get to 21C doesn't seem unreasonable. 21C is quite hot when energy prices are as high as they are. I would aim for 18C to start with. Based on what you know already it will take less than 2hrs for the stat to see the this temperature.

The radiators that aren't warm aren't contributing to heatin the house up, and this may account for the slower time to heat up the house. Have they got Thermostatic Radiator Valves (TRVs) on them? They might also be blocked. it sounds like you are new your house, and hence those radiators may not have worked for years. 

badmemory

The radiators, especially if they have been turned off at some point, may just need bleeding.

macman

You don't say how many rads, or where the cold ones are, but I'm guessing that maybe a quarter of your system is therefore not functioning, which is hardly efficient.
12C to 21C is a big jump, but I'm wondering why the house is so cold in it's unheated state? For it to drop that low in the recent relatively mild weather indicates that you have very poor insulation.
Drop the 'stat to 20C and you can probably run it for 4 hours at no greater cost: every 1C extra costs maybe an extra 10% on your heating bill.

kmb500

BikingBud said:

12deg seems cold considering it is still very mild outside, how are you measuring this?

Are you aiming for 21 deg throughout the house or comfort? Are they the same thing?

Where is the thermostat and where are you spending most of the time?

What powers your heating?

Do all rooms have rads, what are the TRVs set at?

Having a rad adjacent to a stat with a TRV set high may shut off the heating before other rooms get chance to warm up,.

Where are the 2 that are not warm?

I am measuring it just by the honeywell thermostat. I assume the temp sensor for the thermostat dial is actually on the dial, not somewhere else.

I'm not aiming for any particular temperature as long as its comfortable. I just thought 21 degrees seemed like a reasonable room temperature.

Is 12 degrees cold given that it hasn't gone above 7 degrees today? I would have thought this is normal.

Heating is powered by a new-ish oil boiler that is working properly; we had a boiler service last week.

All rooms have radiators and the TRVs are set at max.

The layout of the house is like this. Its a bungalow. Apologies for the poor art skills. The cold radiators are the blue lines, the red ones are warm.

Also, the lounge feels very cold even though both radiators seem warm. It does have double doors to the garden (covered by curtains and a door draft).

I spend most of the time in the evening in the office so I've mainly been keeping the heating off and using an electric heater (i.e. close the office door, run the electric heater for 10 mins, and it keeps the room warm for a couple of hours) as this seems more efficient than heating the whole house. But when I go to bed its freezing in my room, and also when we watch the TV in lounge its cold too.

kmb500

It's now been off for 1 hour and house temp has dropped from 20.0 to 17.5 degrees. Does that sound right?

Spoonie_Turtle

I can't comment on the heating system but those double doors to the garden could probably do with an extra layer or two pinned to the curtains, depending on how thick they already are.

theoretica

A bungalow has a lot more wall and roof to loose heat through for the same floor area than a terraced house. What is your insulation like? 

kmb500

theoretica said:

A bungalow has a lot more wall and roof to loose heat through for the same floor area than a terraced house. What is your insulation like? 

I don't know what the insulation is like other than that our windows our single glaze (and we have some quite large windows in the office). The EPC rating is E. We don't have access to the loft so don't know what insulation is up there.

Is this poor heat loss normal for a bungalow? Is it worth asking my landleech if they can assess the insulation? (Not that I would expect a landleech to invest any money in that)