Not enough Heat

[SimonG]

To the OP. Has the boiler been commissioned and set up correctly? If it's not a modulating one then they run on a range of outputs. Different nozzles and settings will give you different outputs.

 

[Worcester]

Silly question... Do the radiators close to / in the same location as the room stats have TRV's on them?

 

[Worcester]

Aha !!!!

All radiators have TRVs.

 

[Nostrum]

Oil boilers don't modulate, you can only change the fixed output by changing nozzle sizes. Yes, they exist, but not in any great numbers here in the UK.

Even the blue flame technology is fixed output as far as I'm aware (Firebird have just launched one)

If the rads are at the right temperature and the room is cold, the rads are undersized or all the windows are open.

 

[Nostrum]

Actually, reading the post again; they may be sized accordingly, depending on what temperatures the rooms were designed for. Generally, 18 degrees is sufficient for bedrooms, 21 degrees for others. How hot do you find you need it to be to be comfortable?

25 degrees is pretty warm !

 

[Norcs]

Yes .. sounds like its working fine. The OP should invest in some wooly jumpers.
Modulating oil boilers. LoL.

 

[Wagger]

Thanks doitmyself. Answers. Will have to ask installer but when I said we wanted to get it up to 25c he didn't say that was not possible.
Temp outside been 5/8c not very cold.
Worcester Bosch Greenstar Danesmoor Ext 12/18
I saw the installer carry out the work when he came back to have a look at it but, of course, I don't know how well he did it.

 

[Wagger]

Greenstar Danesmoor ext 12/18.
9 rads - 1 v small.
Yes, has been commissioned separately

 

[Norcs]

he didn't say that was not possible

OOh dear. He shot himself in the foot there.
Was that before or after the installation was carried out?

Bigger rad needed probably.

 

[Wagger]

Yes they do but installer said that this was OK providing the TRVs were left o highest setting -5. What do you think?

 

[Wagger]

He said after

 

[Wagger]

Yes 18 in beds Ok but 21c not comfortable enough to sit in watching telly. We aimed at 25 to get system running full bore but can not get above 21, sometimes only 19. System seems to switch off when it reaches this level even though room stat hasn't reached 25. I would have expected it to keep belting away!

 

[Worcester]

See my previous posts..

Wagger you state that ALL radiators have TRV's

Were the stat is located there shouldn't be any TRV's the system is fighting itself.

Any well designed system should be able to get a house up to 25, especially with an outside temp of 5-8, for older people that are sedentary during the afternoon we ususally set their stats to 23 for the pm (we use programmable stats so can set multiple heating levels per day)

The system should have been designed for between -1°C and -3.8°C depending upon location.

 

[Norcs]

Fit a stove.

 

[lame plumber]

if all the rads have trvs, then the rad in the hall/room with the room stat will be fighting the trv for starters. Other option, buy some jumpers.................

 

[SimonG]

Did you get your certificate from building control?

 

[NRS]

Try removing TRV heads from rooms that are cold; sounds like trv's are shutting down before your desired room temp is reached. worth a try !!

 

[gmartine]

As lame said if TRV is in hall with stat, no boiler interlock.

Completely remove TRV head in the hall and see.

 

[Davide13]

Will a TRV open on 5 start to close then? Surely it will allow maximum flow all the time or are they calibrated to close even on max.

 

[Worcester]

Will a TRV open on 5 start to close then? Surely it will allow maximum flow all the time or are they calibrated to close even on max.

They'll close even on 5 and that could well be before the room achieved temperature because they are measuring the air temp immediately adjacent to the rad, not the room temp, hence a need even with TRVs for proper balancing