water too hot checklist

[filthyturk]

Hot water is absolutely scalding!!!!!!!!!!!
so far I have:-
tried turning down cylinder stat but nothing changed.
tried turning CH off and nothing changed.
there are x2 zone valves but I dont know which is which, as the levers on both dont move when I switch off either CH or HW at the controller.
I fiddled with the cylinder stat control knob and it clicks when it reaches past 80deg.
tried turning down stat on the boiler (ikon) but nothing happened.
I dont think the immersion is on, the spur is switched off.
I know this is stupid but am i supposed to wait a few hours for something to happen ? i even tried leaving the hot tap on to see if that would help somehow
I had the boiler serviced before christmas
I have read numerous posts regarding this subject and I'm afraid I still need your help
I would prefer to have a crack at this myself as it seems there is some electrickery going on, however, any more scalds and it's time to call in the pros
thanks in advance

 

[Diyisfun]

The hot water will not just go cold, you will need to use it.
Do the t/stats click when you turn them.
Im not a plumber/heating eng, but It cant be difficult.
Ensure immersion is off.
Turn t/stat down on hot water tank.
Turn central heating off.
Use hot water, then see if the boiler fires up to replenish, it shouldnt because you have turned the stat down, if it does replenish it could be a stat problem.

===
Any way I have just bumped your thread, you should get expert advise soon.

 

[filthyturk]

Ok, I turned the cylinder stat all the way down, turned the CH off at the controller and YES the boiler did fire up after a few minutes of hot water use. Is this suggestive of a stat problem as in previous post?

 

[Diyisfun]

I would have said stat issue, do you hear it click when you turn it up/down

 

[filthyturk]

It clicks when you rotate it past 80deg

 

[Diyisfun]

So the water in the tank is at 80, far to hot (if we are talkin C not F)

 

[filthyturk]

Far too hot is right. I would have thought the stat would click a bit closer to perhaps 60/70deg, could it be a calibration problem? I can probably pick up a new stat for less than a score, so maybe thats what I'll do. Unless there is something glaringly obvious that I've missed

 

[Diyisfun]

If this has always been like this then its a calibration issue or the position of the stat. If its just become a problem, I would suggest a faulty stat.
Im surprised that no heating engs, have given their views.

 

[seco services]

Could be a stat or zone valve fault.

Does the boiler still fire up if hw off at programmer ?

 

[filthyturk]

Ok peeps this is the latest.

I turned off the HW as suggested and the boiler DID fire up after I turned the hot tap on
The CH was also switched off and the cylinder stat was turned down to its minimum.
I know for sure that turning CH off at the controller works, cos basically the temperature drops. I switched the HW off at the controller and the boiler is still deciding to heat water. Is it one of the valves or could it possibly be the controller?
Like I said before, I dont know which valve controls what, can post pics if that helps. Did read in a different post a squirt of WD40 on 'spindle' may help if the valve was stuck in the open position.

 

[filthyturk]

One more thing that may be relevant, when I turn the knob on the stat til it clicks, a whirring noise starts in one of the valves. Not sure which one as they are quite close together.

 

[seco services]

Give us some pics.
Some of your description don't quite make sense.

 

[filthyturk]

here are some pics

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• filthyturk
• 14 Feb 2012
• 1

Untitled

• filthyturk
• 14 Feb 2012
• 1

Untitled

• filthyturk
• 14 Feb 2012
• 1

The little levers on top of the valves do not move at all when switching CH/HW off at the controller/programmer. Thought I'd include the pump in case its relevant

 

[HERTS P&D]

With the age on that cylinder, me thinks that could need changing before a leak occurs.

Andy

 

[twgas]

you need a much more systematic approach than people saying , sounds like this, might be that etc.
Turn both heating and hot water off at the programmer and allow to cool, an hour should suffice.
Then turn the HW on at the programmer - does the boiler fire (it will take about 10 seconds after turning on)?