How long does your central heating take to heat the house?

MX5huggy

Investigate cavity wall insulation, you’ll be toasty with with this installed. 

twopenny

I've had both. The cavity wall insulation does keep the house warmer when the heating is on.

If like me it was a south facing house I found I had to use the heating longer during the year because I wasn't benefiting from the warmth of the sun autumn and spring. It kept the suns heat out.

I did use a foil sheet behind the radiators during winter. It made a significant difference to the amount of heat given out instead of heating the wall. I was dismissively told it would be a miniscule amount but it was a lot warmer and quicker to heat the air.

Jeepers_Creepers

ic said:

Have a dig in your settings on the bosch app for "optimum start" and enable that.  That way you set the programme for the time you want the room to be a temperature - say 7 am at 21 oC.  The thermostat will learn how quickly your system takes to heat up, and adjust the time it actually kicks in based on the weather and the temp inside the house, so on a very cold winter's night it might kick in at 4 or 5 am, whereas in the spring it may only turn the heating on 20 mins before hand as the house won't be so cold to start with.

Another thing to look for in the app is the setting to enable "weather compensation".  If available (depends on the your boiler model) it'll use the local weather conditions reported on the internet to adjust the flow temp of the water in the rads.  On a very cold day, it'll increase towards the max, whilst on a mild spring day the temp will be be much lower.  This is more efficient as your boiler will run more often in condensing mode, and should result in a more comfortable house.  Make sure the dial on the front of your boiler is set up towards max for the rads - as this is ultimately the maximum it'll run at.  (This basically automates what Jeepers_Creepers is talking about with tweaking the flow temp - let the thermostat do it for you second by second with the ever changing weather conditions).

If you have 'optimum start', then your system will learn when to turn itself on so as to get to the required temp at the required time. However, if you set the overnight temp as low as 14oC - and if the house does fall to that - it will still take a long time for it to get back up to temp for the morning; it'll make itself fire up earlier, just as you could do as one solution.

I'd suggest, tho', that a min overnight temp of, say, 16oC would be better for you and the house itself, and the boiler would then likely come on a few times during the night (when it's freezing outside certainly), but could wait a little longer before firing up fully to get the house warmed up in the morn.

TELLIT01

Our overnight temp is set at 16 and I can't recall the heating ever kicking in over night.  Evening temp is set at 20.

macman

I can only restate my case: if, after a day of 'normal' heating, with the house up to 21C, the temp drops as low as 14,5C overnight, then, even given that you tested the system on one of the coldest nights of the year so far, when the rate of heat loss will be at it's highest, the rate of heat loss is unacceptably high. A 4 b/r detached property, large or small, obviously has a high proportion of external walls, so I would get cavity wall insulation done as a priority.

If you want to heat rooms as high as 21C, then it's going to cost you more: remember that the general rule is that a 1C reduction in temp will save you as much as 10% in gas consumption.

Phil4432

I'm a 4 bed linked, made the conversion from warm air to CH a few years back.  Thank Christ for that.
I have 9 rads and a towel rad, temp on boiler at 67C when its around 0C outside.  Takes about the same time for my house to heat up, and that's without insulated blinds which I'm going to invest in when I can.  So I'd say yours is a little slow.

After the initial insulation, I paid to have a couple of rad switched around, to get the balance of heat in the house just right.

My loft is packed with insulation though.  Gets a bit too hot in summer.  You could add my loft insulation and insulated blinds, but check your summer temps first.  You may find yourself nice and cool and the trade off would be worth it. 

TanDiy

UPDATE: Thanks for all the information. Last night, the temp outside was a reported 0 degrees but the temp inside only dropped to 16. I also reduced the flow temperature down to 75 degrees yesterday. The heating company left it at full 88 degrees saying that the stat will run it at the heat it needs.  Heating came on at 5:30 with thermostat set to 23 degrees and heated as below
05:30 16.0 degrees
06:30 19.0 degrees
07:00 19.5 degrees
07:45 20 degrees
08:10 20.5 degrees
08:50 21.0 degrees
Take on board what macman is saying. The stat was only set to 23 degrees as we are trying to see how quick it warms up and whether it can reach a higher temperature. We will not be running the heating at 21 degrees going forward; it's warm enough on 19 to 20. The system was only installed a couple of weeks ago and we are just trying to check it is all ok and heats up as it should. The reason for this is we have found that the radiators installed in the bathroom and downstairs toilet do not heat the rooms. If we leave the bathroom door open then it draws heat from the landing and the room heats up, hence why we started to think the radiator might be too small. We checked the radiator manufacturers website and their calculator suggests a much bigger radiator than that recommended and installed. It also states that a couple of the other radiators in the main living rooms are also slightly smaller than they recommend so we just wanted to be sure that it is working correctly. Also, when we turn the stat up, the temperature does not seem to rise beyond 22 (not that we would need this). Thanks again for all the useful information.

macman

I think this rather proves my point. With the slight exception of the 2 undersized rads, which presumably make only a small contribution to the overall system output, the overall problem is not inadequate input, but excessive leakage.
PS: you won't get the house to heat up any quicker by setting the 'stat up to 22C, or even 30C. The boiler will run at near maximum output until it reaches the demand temp, and then modulate down.

Ganga

Our 2 bed semi has been dropping to 14/16 degrees overnight and we are running at 22.5/23 degrees during the day ,takes about one and a half hours to reach max. mind we are in the north east and it was minus 4 degrees the other night .We are both pensioners and posibly feel the cold more but would rather spend a bit more on the heating than sit in the cold .

Jeepers_Creepers

From what you say, it does sound borderline in being able to cope. It's a shame, because having 'oversized' rads has more than one advantage - the other is to allow the boiler to run cooler and hence more efficiently. 

How far you wish to go with changing the sizes is up to you. There's obviously the additional cost, and also some degree of disruption. If you can fit a rad of similar width but just more powerful - extra convector fins, stuff like that - it makes life a lot easier. Ditto for bathrooms - a towel rad with a panel would give the best of both worlds (what's in there at the moment?). 

In theory (and in practice...) it would appear the plumber didn't do an ideal job, but whether there's any mileage in pursuing that I just don't know. Perhaps he'd agree a special rate - cost price rads and reduced labour charge?