Vaillant ecotec Boiler thermostat knob broken.

[MickBrown]

I had my heating on for the first time yesterday, it did not warm up much so went to check the central heating temperature set on the boiler. It was at 38deg, it had been recently serviced and I assumed the engineer had left it at that temperature. Went to turn up the thermostat and the knob fell off in my hand, it would not push back on and was obviously broken. Tried to turn the spindle inside but it would not move. The boiler is a Vaillant ecotec and is 18 months old. The knob must have been broken when the engineer serviced the boiler, not saying he broke it but it would have been obvious so annoyed he did not mention it. I am checking with Vaillant to see if it still under warranty, if not could I change it myself (assuming I can get the part). I am competent to change something like that but it would mean taking the cover off and I know what you Gas Safe engineers are like when taking the cover off is mentioned by a non Gas Safe engineer.

 

[nysk2008]

Think the part number is 117319 (PK3); not sure if you have to the casing off as never chenged these on a valliant

 

[ASJ]

I have the EcoTEC Pro, and on mine, taking the cover off doesn't give you acess to the control knob anyway. I think it will just be a push on part that you can do your self.
My warranty is 5 years, they might claim its been boken by mis-use but its worth a try.

 

[MickBrown]

I think there may be a problem with the thermostat itself, I would have thought that I could turn the thermostat by poking a screwdriver in the hole and turning it. However when doing that it is solid and nothing moves although I did not exert a lot of pressure as did not want to cause further damage. I may try prising the knob off the water thermostat and see if that will fit, it looks the same knob. I can compare the two as well to see what may be broken. I am away for a few days so will try when I get back.

 

[ASJ]

I'm Not sure exactly what goes on in there but i think it will be an electrical potentiometer (POT) (rather than a thermostat that may seize up). I know mine turn so easily they actually feel quite cheap, is it possible there is still a bit of the borken knob jamming it up somewhere?

 

[jboconel]

Did you solve the "boiler thermostat knob broken" problem . if so, how?

 

[MickBrown]

I found the part on the Vaillant web site and ordered from Plumb Center. You had to order a packet with 3 knobs, 2 thermostat and one on/off, don't know why they think you need all 3, cost £15. Took off front cover and electrical panel drops down, removed broken end of the knob and pushed the new one in from the front.

 

[washere]

EASY & CHEAP FIX:

+ Temporary Fix
​

The knob broke on me, ecotec 824. It is easy to fix, even if you are not handy or elderly or a lady who does not do DIY, most ecotec models conform to below instructions:

* Switch off boiler at front (lower right) & also switch off external plug/switch if accessible

* Unscrew the single screw at front-bottom of boiler body

* Slide front metal panel up & remove (does not affect plastic knobs / control panel)

* Unclip the 2 large side clips holding the white plastic box to the body at bottom.
Pressing the metal body in helps ease it off by hand, if not strong use screwdriver or butter knife (if you have no screwdriver)

* The plastic box slides out & down, stops at an angle, do not press it all the way down, leave it be

* Unclip the 4 Plastic clips on the white box: 2 on top, 2 on the sides, use your flat screwdriver again gently
Open plastic box

* Green Motherboard & Control panel etc are now visible: Remove the broken stem
It should still be in there in most cases
BE CAREFUL YOU GET THE RIGHT ONE (orientations upside-down, can mistake)
Gently move the broken stem before removing: To make sure you got the broken one
BROKEN ONE SLIDES OUT EASY (don't drop it into box)
Chances are it will be extractable from behind motherboard because like mine the thicker end broke off with knob

* You can turn it with the stem to required temperature for a temporary fix



* Remove & hold on to the broken stem to complete temporary fix in next steps

* You can now close up the boiler again by clipping the box back in

* Slide the large front metal panel slightly up before sliding into place, make sure it is clicking at top of boiler into place
No gaps
Screw in the front bottom screw again

* You can turn on the boiler again

* Completing Temporary Fix:

* Chances are your broken stem is about an inch & a half like mine

* Take some sticky tape: I used guerilla tape but can use any tape: duct, masking, electrical or even normal paper tape (scotch). Whatever sticky tape

* Wrap lots of tape at the few milimetres on top of broken stem: TO FORM A KNOB to control temperature
+ This also stops it falling in again, saving you to open up the boiler again

* Insert stem & rotate till it clicks into it's slot

* You can wrap a little more tape further in from the sicky tape knob you wrapped: KEEPS IT TIGHT & IN PLACE

Now You have a working knob again.

* You can also use a long piece of small square wood, shaved to fit at end, if your stem is too short (unlikely, they all break at the same place as mine)
Just need to shave the end precisely to fit


CHEAP PERMANENT FIX:

* Now you need to buy knob to replace
The set is usually £7 to £8 for all 3 knobs plus postage or have to go pickup

* That is using google shop search. BUT you can buy only the one knob:
The one knob (with stem) is about £5 BUT:

* If you search ebay uk for:
Vaillant knob
Can try other words like ecotec knob or model number etc, but narrows down your choice
Just search for: Vaillant knob

* You see lots of sellers, but then:
Sort by LOWEST PRICE as I did at top drop-down menu, change from Best-Match default

* Most of them might not look the same on the inside:
I bought one that did not have inner central rings like my broken one, I bought it yesterday morning
It arrived this morning. I paid £2.50, arrived in a box and the 24-hours royal mail delivery signed for was free

* There was even a green one (not beige) which I am sure would have fitted, it was only £2 delivered!
I splashed 50 pence extra for the original colour.
Most single knobs were about £4.50 to £7 on ebay
The green knob is actually not bad for quickly knowing which knob is which, depends which on your taste/need

* Once you get the new knob:
No need to open up the boiler again

* Mine seemed to have a thicker stem than the broken one with tape-knob
It did not go in
However as I rotated it to fit into it's slot shape (has a slit on a side, need to align correctly) IT FITTED IN
see where the slit on the broken stem is as you remove it
Can put a bit of oil or butter on the stem to fit easier, but not needed really

That is it, you have an easy temporary fix ANYONE CAN DO +
A permanent fix within a day or two for a couple of quid.

Sorry about any typo, have to finish cooking now. Hope this helps someone.
Good luck & All the best.

 

[ShaunCorbs]

EASY & CHEAP FIX:

+ Temporary Fix
​

The knob broke on me, ecotec 824. It is easy to fix, even if you are not handy or elderly or a lady who does not do DIY, most ecotec models conform to below instructions:

* Switch off boiler at front (lower right) & also switch off external plug/switch if accessible

* Unscrew the single screw at front-bottom of boiler body

* Slide front metal panel up & remove (does not affect plastic knobs / control panel)

* Unclip the 2 large side clips holding the white plastic box to the body at bottom.
Pressing the metal body in helps ease it off by hand, if not strong use screwdriver or butter knife (if you have no screwdriver)

* The plastic box slides out & down, stops at an angle, do not press it all the way down, leave it be

* Unclip the 4 Plastic clips on the white box: 2 on top, 2 on the sides, use your flat screwdriver again gently
Open plastic box

* Green Motherboard & Control panel etc are now visible: Remove the broken stem
It should still be in there in most cases
BE CAREFUL YOU GET THE RIGHT ONE (orientations upside-down, can mistake)
Gently move the broken stem before removing: To make sure you got the broken one
BROKEN ONE SLIDES OUT EASY (don't drop it into box)
Chances are it will be extractable from behind motherboard because like mine the thicker end broke off with knob

* You can turn it with the stem to required temperature for a temporary fix



* Remove & hold on to the broken stem to complete temporary fix in next steps

* You can now close up the boiler again by clipping the box back in

* Slide the large front metal panel slightly up before sliding into place, make sure it is clicking at top of boiler into place
No gaps
Screw in the front bottom screw again

* You can turn on the boiler again

* Completing Temporary Fix:

* Chances are your broken stem is about an inch & a half like mine

* Take some sticky tape: I used guerilla tape but can use any tape: duct, masking, electrical or even normal paper tape (scotch). Whatever sticky tape

* Wrap lots of tape at the few milimetres on top of broken stem: TO FORM A KNOB to control temperature
+ This also stops it falling in again, saving you to open up the boiler again

* Insert stem & rotate till it clicks into it's slot

* You can wrap a little more tape further in from the sicky tape knob you wrapped: KEEPS IT TIGHT & IN PLACE

Now You have a working knob again.

* You can also use a long piece of small square wood, shaved to fit at end, if your stem is too short (unlikely, they all break at the same place as mine)
Just need to shave the end precisely to fit


CHEAP PERMANENT FIX:

* Now you need to buy knob to replace
The set is usually £7 to £8 for all 3 knobs plus postage or have to go pickup

* That is using google shop search. BUT you can buy only the one knob:
The one knob (with stem) is about £5 BUT:

* If you search ebay uk for:
Vaillant knob
Can try other words like ecotec knob or model number etc, but narrows down your choice
Just search for: Vaillant knob

* You see lots of sellers, but then:
Sort by LOWEST PRICE as I did at top drop-down menu, change from Best-Match default

* Most of them might not look the same on the inside:
I bought one that did not have inner central rings like my broken one, I bought it yesterday morning
It arrived this morning. I paid £2.50, arrived in a box and the 24-hours royal mail delivery signed for was free

* There was even a green one (not beige) which I am sure would have fitted, it was only £2 delivered!
I splashed 50 pence extra for the original colour.
Most single knobs were about £4.50 to £7 on ebay
The green knob is actually not bad for quickly knowing which knob is which, depends which on your taste/need

* Once you get the new knob:
No need to open up the boiler again

* Mine seemed to have a thicker stem than the broken one with tape-knob
It did not go in
However as I rotated it to fit into it's slot shape (has a slit on a side, need to align correctly) IT FITTED IN
see where the slit on the broken stem is as you remove it
Can put a bit of oil or butter on the stem to fit easier, but not needed really

That is it, you have an easy temporary fix ANYONE CAN DO +
A permanent fix within a day or two for a couple of quid.

Sorry about any typo, have to finish cooking now. Hope this helps someone.
Good luck & All the best.

Wrong and I guess your gas safe registered by taking the case/ front off the boiler

 

[Harvest Fields]

Breaking the law doing so.

 

[ShaunCorbs]

@Lou any chance you could wave your magic

 

[Harvest Fields]

It's a lost from 2013 how the hell do they keep popping up??

 

[ShaunCorbs]

It's a lost from 2013 how the hell do they keep popping up??

Google each forum post (in open parts) is on google

 

[Harvest Fields]

Google each forum post (in open parts) is on google

Just did. 3rd post down on google. How annoying. Is there not a way they auto close after 12 months??

 

[ShaunCorbs]

Just did. 3rd post down on google. How annoying. Is there not a way they auto close after 12 months??

Don't think so

 

[Lou]

Done.