House Slow to Warm Up

[smckeown]

If it takes a long time for temps to drop once heating is off, I assume good levels of insulation.

Check the water temp setting / dial on your boiler, its probably set too low

[Sheepshanks]

For a 1960's house the rate of fall seems remarkably low - be interesting to know the outside temp when that graph was produces.

My house is 1967 and gets cold fast, but then we keep it warmer than the OP's house so we'd be starting from a higher temp - typically 21C. On cold (around 0C) night ours will drop to 14C downstairs but it'll still be 16C upstairs.

[chris.tarry85]

The graph was from Sunday, it was snowing in the morning and certainly less than 5 degrees outside.

We have topped up the insulation and have less than ten year old windows, so it's not all 1960's standard.

The radiators (especially where we don't have micro bore piping) are hot rather than just warm, so I don't think its a flow temp issue.

[V8RX7]

markcoznottz said:

Always best to fit the biggest doubles that will will fit, it will save money in the long run.

You can always turn a double down but you can't turn a single up.

Rubbish - my rads are probably double the required size at single 1800s because the windows are 2100 and anything smaller looked silly IMO - why would oversizing them by approx 4x the requirement be better ?

Following your logic two 1800 double rads would be better still, why not 3 or 4 of them ?

[smckeown]

Is the thermostat located in a very cold room?. Irrelevant of the stats, does the house feel cold / takes a long time to heat?

[V8RX7]

Jesus wept...

How big is the lounge - how big is the rad

How big is your bedroom - how big is the rad

[jeff m2]

chris.tarry85 said:

Thanks All, to answer some more questions:

- Fairly modern combi boiler
- Detached house

I think the next step will be to replace some of the single panel radiators with doubles.

Might be cheaper to have it turn on ten minutes earlier!

Assuming you have half decent insulation have you considered just maintaining the temp instead of letting it cool then paying to re-heat it.

I set my temp & humidity in October.............

Maybe buy a couple of max min thermometers and see what's really happening in different parts of the house, Low tech approach.

[gareth h]

Not sure if it is the case here, but it can be down to the thermal mass of the building.
A few years ago a friend bought a thatched place that was a weekend retreat, he had very high oil consumption despite only turning the heating on when they arrived on Friday and off on Sunday.
I did the heat loss calcs and although not great it wasn't as bad as I thought it would be.
Had me baffled until I looked at the thermal mass of the thick chalk walls, what was happening was the walls were absorbing heat and taking 2/3 days to come up to temperature, during this time the house never really got warm. Then the heating was turned off and for the next couple of days the house was unoccupied but toasty!
I suspect the gardener was also half inching oil out of the tank!

[jeff m2]

gareth h said:

Not sure if it is the case here, but it can be down to the thermal mass of the building.
A few years ago a friend bought a thatched place that was a weekend retreat, he had very high oil consumption despite only turning the heating on when they arrived on Friday and off on Sunday.
I did the heat loss calcs and although not great it wasn't as bad as I thought it would be.
Had me baffled until I looked at the thermal mass of the thick chalk walls, what was happening was the walls were absorbing heat and taking 2/3 days to come up to temperature, during this time the house never really got warm. Then the heating was turned off and for the next couple of days the house was unoccupied but toasty!
I suspect the gardener was also half inching oil out of the tank!

Yep, many people have the concept they are just heating the air, everything in the house is being brought up to temperature.(every time it turns on)

This is very much more apparent if you have central air conditioning during the Summer, if you turn it on and off it will empty your wallet really quickly and the comfort level is really not good.
After I managed to convince my wife what was happening our electric bill was cut by 30% by setting it and leaving it.
A very comfortable house and smaller bills, but I still have a confused wife who refused to google kinetic energy.

[Alucidnation]

Just leave the heating on 24/7 at a comfortable temp.

You could always knock it back a degree or two whilst you are out and turn it up when you come home.

[V8mate]

iambigred said:

My house is similar, takes an age to warm up and never feels "cosy" unless the heating is on for ages. Once it's up to temp it does seem to cool down slowly. The stats below are from a particularly cold day last year:



What type of boiler do you have? In my relatively modern house I have a system boiler and found that the automatic bypass valve was either faulty or wasn't set correctly, so water was being returned to the boiler too hot and it was short-cycling. Performance has improved slightly since replacing the valve but still not happy with it. I suspect my radiators are undersized but I haven't got round to measuring them and calculating the current/desired amount of BTU for each room.

You keep the house at 19.5 overnight? How do you sleep? I'd have such disrupted sleep being so warm.

My thermostat is set at 19 in the evening - I'd be surprised if we hit 17-18 - and then goes off completely just before 10pm. And the bedroom window is open all year round save for the rare easterly wind blowing straight in.