Any ideas why my boiler won't heat the hot water above 55 degrees c. Potterton
prima 40 b running y plan stored heating system. All stats and valve working
ok but boiler will just keep churning on if tank stat is set to 60 and boiler
stat set on max. Was OK last year. Also have to keep hot water on with CH
otherwise stored temp gradually diminishes to about 40.

--
for full context, visit https://www.homeownershub.com/uk-diy...h-1255520-.htm

In article , Graham
m wrote:
Any ideas why my boiler won't heat the hot water above 55 degrees c.
Potterton prima 40 b running y plan stored heating system. All stats and
valve working ok but boiler will just keep churning on if tank stat is
set to 60 and boiler stat set on max. Was OK last year. Also have to keep
hot water on with CH otherwise stored temp gradually diminishes to about
40.


a leak between primary & secondary circuits?

--
from KT24 in Surrey, England

On Saturday, 9 December 2017 17:14:05 UTC, Graham wrote:
Any ideas why my boiler won't heat the hot water above 55 degrees c. Potterton
prima 40 b running y plan stored heating system. All stats and valve working
ok but boiler will just keep churning on if tank stat is set to 60 and boiler
stat set on max. Was OK last year. Also have to keep hot water on with CH
otherwise stored temp gradually diminishes to about 40.

the obvious candidates are the primary stat & tank stat. A less likely candidate might be pump failing or crudded up resulting in the boiler quickly cutting out but pump keeps running - that would cane CH output as well though. Muck in the DHW cylinder exchanger is also possible. Telling us a lot more about the system would help.

So would using anywhere else to access this place from. Most regulars have h o h blocked.


NT

On Sat, 09 Dec 2017 17:14:02 +0000, Graham wrote:

Any ideas why my boiler won't heat the hot water above 55 degrees c.
Potterton prima 40 b running y plan stored heating system. All stats and
valve working ok but boiler will just keep churning on if tank stat is
set to 60 and boiler stat set on max. Was OK last year. Also have to
keep hot water on with CH otherwise stored temp gradually diminishes to
about 40.

The stat on the boiler itself? If it isn't producing water at a high
enough temperature, it'll never get enough heat to the HW.



--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

On 09/12/2017 17:14, Graham wrote:
Any ideas why my boiler won't heat the hot water above 55 degrees c.
Potterton
prima 40 b running y plan stored heating system. All stats and valve
working
ok but boiler will just keep churning on if tank stat is set to 60 and
boiler
stat set on max. Was OK last year. Also have to keep hot water on with CH
otherwise stored temp gradually diminishes to about 40.

Start by checking the flow temperature of the water out of the boiler
(i.e. the actual pipe temp, not the indicated on the dial temp).

Basically you need to find out of this is a lack of flow temperature
problem, or a controls problem / cylinder problem.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 9 Dec 2017 18:35:09 GMT, Bob Eager wrote:

On Sat, 09 Dec 2017 17:14:02 +0000, Graham wrote:

Any ideas why my boiler won't heat the hot water above 55 degrees c.
Potterton prima 40 b running y plan stored heating system. All stats and
valve working ok but boiler will just keep churning on if tank stat is
set to 60 and boiler stat set on max. Was OK last year. Also have to
keep hot water on with CH otherwise stored temp gradually diminishes to
about 40.

The stat on the boiler itself? If it isn't producing water at a high
enough temperature, it'll never get enough heat to the HW.

It's worth adjusting the stat knob and listen for the click of the
contacts; see if the figure equates to the temperature of the cylinder
under the stat.

I had the contacts on a Danfoss ACT go open circuit (sometimes!).
Purchased a replacement off eBay and found that the calibration was
wrong; reading 15 to 20 degrees high; another was sent without quibble
and not wanting the first one back. The second one was exactly the
same so called Danfoss, explained the issue and they asked me to send
one for investigation. I realized I didn't need to fit the stat to
test it as just held in my hand the contacts were changing over at 50
degrees; my hands are not that hot! I have left one on the cylinder
set to 75; the cylinder temp is a shade under 60.

Note that calling Danfoss since they moved sales and services from
Bedford to Denham needs patience - a lot of it!Only the sales number
was working, the background noise was appalling and it really does
take an awful long time to get an answer whereas they used to be
slick.

Mike

---
This email has been checked for viruses by AVG.
http://www.avg.com