worcester 24i query

[Jambo123]

Hi.
Worcester 24i rsf/ NG combi boiler
approx 6 years old
Temperature adjustment for radiators on front panel of boiler does not seem to be working correctly.
it is set on 1, and the radiators are boiling hot... too hot.
When it is turned to summer setting via the same control, it turns off the heating. so appears to be working.
i have checked B.P's ... all fine. and is modulating down too.
pump speed is set to 3, and is circulating well.
no boiler noises.
Any idea's people?

 

[twgas]

how hot is too hot, have you checked the actual temp with a thermometer?

 

[Jambo123]

no mate. just know its too hot as it is set on 1 and rads are on like it is set on 5!
any ideas?

 

[desmondeng]

Turn mains power off to boiler...

first check the connections to the temperature thermisitor...

its fitted/clipped to the CH FLOW pipe in the bottom section of the boiler. there are two thermistors one on the DHW and the CH FLOW...make sure you identify the correct one.

make sure the connections are clean/corrosion free and reasonably tight..

if this makes no difference you may need a new thermistor
if you boilder is indeed a 24i RSF NG than then the bocsh part number for the CH thermistor is...... 8 716 142 384 0 and the clip part number is 8 716 148 313 0 ... both these can be bought from your local HRPC centre or have a google search for boiler parts ....
Make sure if you fit a new one to use some heat transfer compound ...a small tube of which is available from HRPC or any electrical/electronics supplier...

hope this helps


PS ... the thermistor is the cheapest thing to try first ..it could also be a fault on the PCB...which'll cost alot more but if needed the part number is 8 716 146 300 0 ..