My central heating is taking over my life!!

[chezabha]

Hi...Gas bills have now gone up to £144 per month so I decided to investigate our usage and if the heating system was operating correctly. We live in Scotland so are used to the heating being on day and night sometimes. Our house always seems cold so we genrally have the thermostat up at 30 degrees. Everyone we speak to tells us that they have theirs at 19/20/ or at most 21. I've now amended the settings on the timer for a couple of hours am and 5-9pm. I work from home and sitting in the office with no heating on is terrible, cold feet (Slippers on) cold nose etc. Surely this cannot be normal. We are no longer touching the thermostat and it remains at 21. There was no way however that the house feels like its 21 degrees so I purchased a thermometer. Heating has been on now for 4 hours and the temp is 17.1. During the night with the heating off it fell to 7.
So the question is why is the thermostat saying 21 when actually its only 17.

I've also blocked off our gas fireplace as there was an arctic draft coming through it.

Boiler: Ideal slimline ff250
Therm: Drayton RTS1
Rads: 11
Pipework: Very small diameter plastic tubing
TRV's: Fitted to all except the one in downstairs hall
House: 4 Bed detached (7 Years old)

I've bled the system with no air found. The rad furthest from the boiler genrally never gets hot though and most are usually cold at the bottom. They have all been balanced and TRV's are fully open at 6.

Thought about taking out a contract with British Gas but read too many bad reviews on it. Does anyone have any advice or is there a heating engineer in the Lanarkshire area that could resolve for me.

Any help would be appreciated - and let me know if I haven't given enough info.

 

[LUNAT]

HI

if your house is new then surely boiler or the system has become faulty.forget the 17/19 deg temp at the room stat.room stat could be few deg out of adjusment.
al long as your room stat is on/calling for heat the boiler/rads should be on.

 

[stem]

Think of the room thermostat as a switch. It either turns the heating on or off and that's it. That's all it does.

If the thermostat is set to 21, then the heating will stay 'on' until the room where it's located reaches 21, then the thermostat will turn it off. When the room temperature falls below 21, it will turn it on again.

If the room where there the thermostat is located is 17 degrees, and the thermostat is set to 21, the radiators will be 'on' nothing will change if you turn it up to 30, it will still be 'on'. The only difference is, that it would stay on until the room reached 30 (Possibly by August)

The surface temperature of the radiators is controlled by the boiler thermostat, the higher the boiler thermostat the hotter the radiators. If the radiators don't get too hot to keep your hand on, when the boiler thermostat is on full, then there is a problem with either the boiler, the plumbing it is connected to. It could be as simple as the pump setting being too low.

If the radiators are getting hot, but the house isn't, then either the radiators are too small for the size of the rooms, or you are loosing heat from the house faster than you are putting it in. Think of it as trying to fill a bucket with water when there is a hole in the bottom, it will never be full. You have identified the fireplace as a source of heatloss. What about windows, does your house have lots of glass for example.

For a house to drop from 17 degrees to 7 ovenight is a lot even when it's sub zero outside. I would be asking myself where is the heat going? I would expect a new property to fall by no more than 3-5 degrees.

 

[HERTS P&D]

Have you checked the loft insulation, it should be 270mm.
Doing the insulation is very quick and easy to do with places like b & q having the insulation that is subsidised by british gas.

I know as I've just done mine.

Andy

 

[chris001]

if the furthest rad is the coldest and cold at the bottom, have they been plumbed in a single pipe system? apparently the least efficient way to do things, but i am no expert!

 

[chezabha]

Thatnks for the replies. Ok, so forget the thermostat on the wall. I see that. What I have done that may affect things is turn the knob down on the boiler from 6 to 3. I "assumed" that this would be wasting gas thus giving me a higher gas bill. So I'll turn it back up and see what happens.

The house is insulated but not sure about the thickness of it though. There is I would say an average amount of glass but we only use blinds and not curtains but that has always been the case. It just seems to less efficient in terms of heat and way over double what we were paying.

Ok....away to crank up the boiler and see what happens. Either I'll get to the bottom of this or my wife will leave me..and then I'll just need to heat a one bedroom flat!!

 

[D_Hailsham]

So the question is why is the thermostat saying 21 when actually its only 17.

The stat is saying 21 because that is what you have set it to! If the actual temperature is 17, then there is not enough heat from the radiators.

Heating systems are designed to provide 21 when it is -1 outside. What was the outside temperature when you had 17 on the thermometer?

The FF250 is a 15kW boiler. You can find what size boiler you should have by using the Boiler Size Calculator Post the result

You can also work out the output of all your rads using the Stelrad Elite Catalogue Post the result

What is the diameter of the plastic pipe?

Is it just the visible pipes which are this diameter, or is it all the pipes?

What is the diameter of the pipes at the boiler? NOT the gas pipe.

Who balanced the system?

 

[stem]

So the question is why is the thermostat saying 21 when actually its only 17.

Hmm... Are we missing something here? When you say "the thermostat is saying 21" do you mean you have set it to 21, or that it has an actual display of the room temperature (not the set temperature) showing 21? When a separate thermometer is telling you the room is only 17.

 

[chezabha]

So the question is why is the thermostat saying 21 when actually its only 17.

Hmm... Are we missing something here? When you say "the thermostat is saying 21" do you mean you have set it to 21, or that it has an actual display of the room temperature (not the set temperature) showing 21? When a separate thermometer is telling you the room is only 17.

Hi.. Sorry I meant that the stat dial was sitting at 21 and the digital thermometer I have purchased reads 17

 

[chezabha]

Hi D_Hailsham

The dwelling type is detached with double glazed windows with wood/plastic frames.
The external walls are cavity, no insulation.
The roof is pitched with 50 to 75mm of insulation.
The Dwelling is in Scotland.

The following three major contributors to the heat requirement
are all affected by the levels of insulation.

The WINDOW heat loss is 1.21 kW

The WALL heat loss is 3.14 kW

The ROOF heat loss is 2.11 kW

Note down the kW readings (or print this page) then press your
browser's Back button.

If better insulation is possible, make selections with higher levels of insulation,
then calculate again to see the effect on the boiler size required.

By spending money on, say, more loft insulation you may save money on the
price of the boiler, and you will definitely save money FOREVER on your heating bills.

The required boiler output is 11.23 kW

More to follow.....

 

[chezabha]

D_Hailsham

The temp outside was 5 degrees at the time.

Plastic internal pipes are 10mm diameter on outside and are visible going into the cavity wall. I know this because I wall mounted a tv and nearly drilled into a plastic pipe going from the rad up the internal wall!
Pipes that come out the top of the boiler are copper and 22mm.

I read up on the balancing so did it myself...May not be right though!

I'll need to look more at calculating the rad output before I post, doesn;t look that simple for a novice!

Thanks agian for all who have been posting.

**Update** since turning the boiler up to 6 on the dial I have achieved 20.4 degrees in the house. Rads upstairs seem alot hotter than those downstairs though.

Regards

 

[Agile]

You should not be bleating about gas prices when you have inadequate loft insulation and when you could insulate the wall cavity.

£150 per month in the winter is what should be expected in the winter in a four bed house.

Tony

 

[chezabha]

You should not be bleating about gas prices when you have inadequate loft insulation and when you could insulate the wall cavity.

£150 per month in the winter is what should be expected in the winter in a four bed house.

Tony

Sorry but I wasn't on here to "bleat" about gas prices but to seek advice in general and if adding more loft insulation is one answer I will certainly look at that. Thanks for your input

 

[D_Hailsham]

Those results do not make sense!

Can you post the dimensions you have used:

Length:
Width:
Room Height:
No of Floors:

Did you use the estimated window factor (0.17) or did you calculate your own?

If the pipes are 10mm, you have a microbore system. The reads are fed in groups from manifolds, which are fed from the 22mm main flow and return.

Rad cals are easy, just look up the size in the link I gave. If unusual sizes, just proportion them.

Ah! So you were trying to save money by keeping the boiler turned down!! It doesn't work like that.

Where did you say you lived?

 

[D_Hailsham]

Forgot to mention this. Check out Energy Savings Trust Grant Search for special deals on insulation.