In the cold winter house doesnt seem to go above 15 degrees on thermostat

[discostewart]

Thankyou to everyone who helped me fix my boiler on my previous thread, now im dealing with a more longstanding problem...

I've always been told by gas suppliers etc to have the heating on timed, rather than leave it on all the time on a low tempreture. The problem is at the moment I cant seem to get my house above 15/15.5 degrees according to the hallway thermostat. And even to reach that temp from 10-15 can take 4 hours.

I do suspect that 15 dgrees in the hallway is probably nearer 19 in the rest of house.

Its 2 degrees C outside.
My house is 1903 cavity wall, 3 storey (tower shape) situated on the coast in Kent bythe sea.. It ha scavity walls insulation, siler stuff behind radiators.

I have a potteron profile 100e (c1999, not a combi) fully pumped system.
The radiators all feel hot enough to the touch.
Salius electronic thermostat in hall.

Yet if takes from 4.50 to around 11.00 oclock at night to go from the thermometer to go from 10 degrees. with the boiler running almost continuously (its not a combi). I just received my winter gas bill it was 450 pounds and the house was ok but never particularly warm.

Today i've"
bled the radiators
turned all the ground floor ones up to "full" (not therm valves).
will see if that helps but not sure if i shoud change to full time heating or if that wil be horrendous on cost.

So questions:

1)
These old houses have huge ceilings and the rooms are very large. I acceept some of the radiator sare not as large as they could be but still... any ideas? Is something wrong, or is it just the nature of the beast. The house just seems to lose heat quickly during the night right back down to 10c. Then we start the cycle all over again.

2) After a few hours the boilers overheat stat seems to kick in quite often. I know these old boilers run hot often but is this a sign of something wrong ? The boiler cuts for about 3 minutes a couple of times an hour and then restarts

 

[plumberdan]

Sounds like a faulty roomstat? could need replacing!

Or possibly the boiler stat could be turned down check to see what it is set too.

 

[Deleted member 2053]

There is a whole host of possibilities here. From cold, try running the heating without the hot water, and with the boiler up full. If the system is working moderately well then the boiler should run continuously until the return gets fairly hot. If it doesn't then you are not getting sufficient circulation. If it does then check the rads. If they are uniformly hot then they probably aren't large enough. If not then you are looking at balancing or a flush. This is a very broad brush and others will doubtless give more detailed alternatives but it is a start. As regards gas cost of leaving the system on v turning it off at night, then check the usage at the meter for both options.

 

[DirksPlumbing]

As regards gas cost of leaving the system on v turning it off at night, then check the usage at the meter for both options.

The advice to have strict timing is most of the times just overhauled and useless.
Depending on the house keeping it running to a certain degree does usually offer a better comfort paired with even savings.

My old house (3ft natural stone walls) had a very long reaction time for getting warm. In winter it was always freezing. I had tried to cut the times further and further as my gas bill would not budge.
Finally I gave in and said to myself to skip it and just pay the extra so I at least have a comfortable home. Kept the system on a programmable roomstat heated all the time just with a dip for the night times and for the work time.
My average winter day usage went from 7 cbm down to 6 cbm.
Should have done that a lot earlier.

At other customers that was not so dramatic but I had no customers by now that had not noted at least a gain in comfort for the same bill and some even noticed the gas bill remaining the same even though the prices had been raised.

I think those programmable roomstats are a blessing.
Another customer was sure e needed a new boiler as his was not getting the houe to temperature. The fitted p/roomstat made him think he had a different house at all.

My favourites are the CM907/ CM927 from Honeywell. The CM907 can just be fitted instead of the existing roomstat. Just make sure that it does not get overridden by the existing timer.

The favourite car analogies is driving full blast and then jamming on the brakes hard does save fuel on a very limited amount of cars. Most of them reward gentle driving with a much better efficiency.
In order to get the system saving then you should try to lower your flow temperature to a reasonable minimum but I think this is no option for you as the Potterton most likely has no separate cylinder demand. But you can try to lower the room temperatures via the roomstat to a reasonable but just comfortable temperature as a number of effects will make a continuously heated house feel a lot warmer as a equally temperatured "switched" house. As there would be heat radiation of the walls, no windchill effect through differences between the air temperature and the wall surface temperature.

I do not think that they would make much of a difference in a perfectly insulated kit house with a proper calculated heating system but they definitely do in older houses.

But of course do the above checks before to see if there are malfunctions of the boiler/heating system. The programmable roomstat would still not be any harm as you can simulate even a switched heating with it if you find that to be your thing. It then just acts in the off time as a froststat.

 

[Mike Jackson]

I would imagine the OP has frozen to death by now as this topic is nearly 4 years old.

 

[Dotty]

I would imagine the OP has frozen to death by now as this topic is nearly 4 years old.

I agree. Good answer though Dirk!

 

[DirksPlumbing]

I would imagine the OP has frozen to death by now as this topic is nearly 4 years old.

OMG, how could I dig out this one?

 

[AWheating]

OMG, how could I dig out this one?

LOL, i think we have all done it mate.

 

[SimonG]

Interesting one though as I always get asked the question, should I leave it on or two hours twice a day. Last few years not been an issue as we have had storage heaters. Now having just moved into an old house with gas combi I think I'll be going for a p/stat and doing some data collection.

 

[DirksPlumbing]

Interesting one though as I always get asked the question, should I leave it on or two hours twice a day. Last few years not been an issue as we have had storage heaters. Now having just moved into an old house with gas combi I think I'll be going for a p/stat and doing some data collection.

Bear in mind it takes a few days to settle. And take a note of the outside temperatures as well. I would be very interested in your results too.
If you can lower the flow temperatures for the heating side independently then try to find the lowest suitable point which will be a lot lower than for switched heating. As it has the time to heat gently.