Vaillant ecotec plus problem

[Agile]

If you wanted to discuss your own boiler then you should start your own thread.

If your boiler is outside the warrantee period then you have to pay for any repairs. That seems obvious to me.

Obviously you can pay whatever you like but in London we would charge £84 plus £34 to supply and fit the part.

It can also be caused by other things apart from an orange sensor.

Tony

 

[DP]

It can also be caused by other things apart from an orange sensor.

What other things will throw the F75 fault?

 

[mickyg]

What other things will throw the F75 fault?

duff or blocked pump, blocked canoe filter, blocked lwps, blocked or partially blocked main or plate heat exchanger. Blocked flow or return hoses.
Majority of F75 are the result of dirty systems.

 

[Agile]

Also, and second after dirt, is the EXV being failed or not correctly pressurised.

The sensor colour is actually pink but I wanted to be consistant in following what Dave had said three years ago.

Tony

 

[Bunnyman]

How is the exv gonna affect it then ??

Untitled

• Bunnyman
• 26 Mar 2010
• 499

 

[Agile]

I hoped you would not ask that!

It seems well experienced that it has a significant effect on the pressure change.

I am rather guessing but it probably acts as a reservoir from which the pump can pull extra water to force it into the system thus increasing the pressure on the sensor.

I also suspect it requires a little air on some rads too.

Tony

 

[vxxbcks]

For the benefit of the search, Vaillant have a new sensor for this boiler part number 0020059717. It's no longer metalic and hence doesn't collect deposits (supposedly). It can be fitted to either original or modified (i.e. with the F.75 kit) units I am told.

 

[Madnutter]

Hi I have been experiecing the F.75 issue from a few months after the installation and a little top up resolved the problem, it has been over two years now and the problem has probably occurred less than ten times.

Reason why i am here is because i was going to set the timer and noticed the needle was in the red. I always wondered why the water had to be nearer the last 15% of the grey mark but I never really questioned it too much (wish the numbers were visible) as previous vaillants displayed and would of alerted me sooner somthing was up.

So as the needle was in the red showing me 3.0, 3.1, 3.2 pressure i thought i might aswell bleed the rads but all were ok, so decided to drain some water from the system to bring the needle back into the grey. So after half a cup (150ml) got the pressue to 2.8.

Guess what next morning F.75. Needle sitting happily in the latter grey stages still. did a couple of reboots still F.75. A bit of water and bingo off it goes again but back in the red.

So as i am about 2months out of my 2yr warranty - i guess step one would be to change the Pressure sensor - looks straight forward any advice?

EcoTec plus 831

thanks
M

 

[mickyg]

If you press the "-" button it tells you the exact water pressure. The guage is just a filling guide. This would/should have been explained by your installer. F75 can be a variety of faults, please see my previous post above, all these things will need checking. The original orange sensors were not "faulty" its just the small voltage which they operate on caused it to be slightly magnetic, meaning systems with any contamination were at risk of failure.

 

[Madnutter]

If you press the "-" button it tells you the exact water pressure. The guage is just a filling guide. This would/should have been explained by your installer. F75 can be a variety of faults, please see my previous post above, all these things will need checking. The original orange sensors were not "faulty" its just the small voltage which they operate on caused it to be slightly magnetic, meaning systems with any contamination were at risk of failure.

Hi Thanks for the prompt reply. The system was power flushed prior to installing the boiler at the time, could it be a hard water issue? The water coming out of the rads is crytal clear and you can smell the inhibitor, so not entirely convinced that it is dirt build up?

It is currently reading 2.7bar at the moment. I'll update during the week if you like but earlier today it was saying 3.2!!

 

[Bunnyman]

Hi mate listen to mickeyg f75 is either sensor or pump butusually sensor an they don't go faulty it caused by contaminated water the hole an where they sit means they r susceptible to this

Untitled

• Bunnyman
• 26 Mar 2010
• 499

 

[Madnutter]

Hi, noted. Can I simply remove and inspect the sensor without draining the system, do I have to power down etc, any advice appreciated. Thanks.

 

[mickyg]

the boiler needs draining before you take it out, else you'll get very wet.
My procedure for F75>
Check water pressure, check pump running
Isolate and drain boiler, pump up exp vessel, remove pressure sensor and check, remove LH hose and canoe filter clean and check.
If still not found anything remove pump head and check for debris in impellor.
thats 30mins-1hr work for someone competent.