Combi Boiler flow temp

J30

I have reapplied for the great British insulation scheme and just called my energy supplier to discuss. They said I should hear back by Friday.

also just contacted my local authority and going to wait on a call back to see if I am eligible for any support - although I doubt it but am hopeful. 

Scot_39

I would have thought that 17 to 17.5 would be good enough for some of the house for many folk - and 19 only really required for main rooms - and then probably not 24/7.

Turning up boiler temps will allow more heat delivery.

But so might boosting air flow across radiators by running a normal desk, a so called "air circulation" ( low noise but far reaching flow) fan or bespoke radiator fans to better circulate heat flow.  If against external walls cheap insulted reflective foil radiator backing insulation could help a bit too.

As radiators ( most passive heaters in fact ) tend to pool heat adjacent and above - a good air circulation can reduce that heat pooling e.g. at ceiling levels etc. 

Ceiling fans are another option to reduce that pooling - especially if have older style high ceilings.

Tests in passive closed circulation rooms have shown it's possible that air a few degrees warmer above radiator all the way to ceiling than it is likely to be where needed - e.g. where you are sitting to watch TV or standing to cook etc.   So anything that circulates that high heat - especially away from lossy surfaces can help.

But ultimately as you will know - room heat is simply a balance of heat energy in e.g. via your radiators vs heat losses out - e.g. drafts, conduction through walls, glass, ceiling etc.

But older homes especially are meant to breath - dampness problems etc can develop if not allowed to.

Unless your boiler is running 100% flat out its unlikely to be the boiler (most modern quickly modulate burner flow down to lower power once flow temps established even if not cycling on off frequently - be still using less than rated power)

But it is always going to cost more to heat space - especially as above whole house - to 19 than 17 - for any given level of loss.

So perhaps turning down trvs in less frequently used spaces and delivering more of the boilers heat to main room or rooms and keeping it there via closed doors, draft excluders or thermal door curtains might work better.

Not all insulation has to be expensive, major or structural.

Thermal liners for curtains, thermal door curtains etc, draft tape and door bottom draft excluders (Which iirc recently recommended old wrapped up towels if not fussy about aesthetics etc), window film kits start around £4 etc

I Use thermal lined curtains on main door ( should really upgrade it as single glazed and thin panelled section below - did use film a couple of years - but had to sand and repaint as tape marked surface after 3months in place )  - patio door and main bedroom windows.


My parents old house - now sisters - has cavity wall insulation - mum got it free on a green grant -   Made a noticeable difference - but now have to keep up with external repairs too - like any render or brick mortar issues - so it's not a cost free option.

Alnat1

Another though, does your house have a chimney? A lot of heat can be lost there, so if not in use block it up during these cold spells. 

We have an open fronted type gas fire that is never used. I could have forked out for a "chimney sheep" type thing for about £20 but I've shoved an old cushion up there and attached a large button that dangles on a piece of string to remind me it's there.

Gerry1

Make very careful notes of all the settings then turn the boiler, thermostats, radiator valves and TRVs to the maximum.

If the boiler runs flat out but can't maintain the desired room temperatures then the boiler is too small.

If the boiler modulates down or switches off but the desired room temperatures aren't achieved then the radiators are too small.

markin

Whats the make and model boiler, The size of the house in square meters?  It will be on the EPC

https://find-energy-certificate.service.gov.uk/find-a-certificate/search-by-postcode?lang=en&property_type=domestic

Are the Rads modern with fins?

How long is the heating running time? Is it only 2hrs at a time or set at constant. If your used to more modern houses and running 2 hrs in the morning and 2 in the evening that may not work here.

Has the heating been on for weeks/months already or is the house an ice block and only gets turn on on when its 5c outside or a set date ?

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https://www.gov.uk/apply-great-british-insulation-scheme

QrizB

Gerry1 said:

Make very careful notes of all the settings then turn the boiler, thermostats, radiator valves and TRVs to the maximum.

If the boiler runs flat out but can't maintain the desired room temperatures then the boiler is too small.

If the boiler modulates down or switches off but the desired room temperatures aren't achieved then the radiators are too small.

Further to Gerry1's post, most houses have a boiler which is capable of producing more heat than the radiators can emit. This is quite normal, as it means you have spare capacity for eg. when you're trying to heat the system from cold and simultaneously heat your hot water. But if your system was incorrectly specified, you could have an undersized boiler.

However the problem is more likely to be with the radiators. Running a low flow temperature increases the efficiency of the boiler but reduces the ability of your radiators to heat your house. Turning the flow temperature up to maximum will mean your radiators get the best chance of heating your home. If it's still cold with the flow temperature at max, it looks more like a radiator problem.