Anyone help please F75 fault code on Valiant eco tec plus

[Agile]

The kit is available.

But not normally needed if everything else is working correctly.

I have never needed to use one!

Tony

 

[Steelmasons]

With just an F75 fault I find that the only extra that I sometimes need is a sensor at about £26.

Tony

As you have previously admitted Tony you are not familiar with the vaillant ecotec.

So in most cases you either clean/ replace water switch and all is good?.....bolax. maybe you can ensure the OP that all is required would be a pressure switch.

As i've said before , stop it Tony.

 

[Agile]

I feel I am quite familiar with the Vaillants.

What I said was that I don't go to many interesting faults mostly just the same old common ones!

The sensor is the least common cause of the fault in most that I go to although it often contributes.

Tony

 

[Steelmasons]

The general forum may not see through you Tony but the guys that actually know do.

Wish it was a simple case of fitting a sensor so as to cure most f75 faults (salmon colour then some are problematic). or maybe re- pressurise EV.

Behave yourself.xxxxx

 

[Steelmasons]

With just an F75 fault.

Tony

Just an f75 fault? . Do you not realise how many faults can throw an f75? , says it all really eh.

 

[Agile]

There is just one F75 fault!

But it has many possible causes!

 

[Piers1989]

There is just one F75 fault!

But it has many possible causes!

Tony is right,

there are many things that can cause the fault, it doesnt mean you have to change every part thats a possible cause... thats just guess work and throwing parts.

Cleaning the sensors can solve the issue, as im led to believe its usually dirt/debris in the pressure sensor causing the issue anyway.

Vaillant offer call outs so its worth ringing them directly if you are concerned over prices etc.

Piers

 

[Terry lambert]

As an engineer it can make you look incompetent if you have to return to the same fault three or four times before a fix.

The F75 I had last week.

First visit cleaned sensor, re pressurised vessel - still lock out

Second visit, changed sensor - still lock out but less

This week, change hoses ect

They will expect you to keep returning for the same repair fee, better to fix first time within reason, and warn of possible pump issue to cya

As I've now learnt, if the boiler is a few years old and has rubber hoses, showing this fault, change them. Whether that's new rubber ones for a cheaper fix or F75 kit if the customer is up for it.

 

[pj123]

Thanks guys, got someone local coming out this week.

All The rads are still getting hot so might not be the pump, but not sure, when I fill up the system and put the heating on the pressure gage goes into the red, the pressure then drops to 0.6 /0.5 bar the following day, the outlet pipe outside feels wet, so it might be throwing water out of that pipe.

Least I got someone, I'm no expert and it could be a munger of things, the way I look at it I haven't been paying BG £25 a month for a couple of years so.....

Will let you know how I get on.
Thx

 

[Piers1989]

As an engineer it can make you look incompetent if you have to return to the same fault three or four times before a fix.

The F75 I had last week.

First visit cleaned sensor, re pressurised vessel - still lock out

Second visit, changed sensor - still lock out but less

This week, change hoses ect

They will expect you to keep returning for the same repair fee, better to fix first time within reason, and warn of possible pump issue to cya

As I've now learnt, if the boiler is a few years old and has rubber hoses, showing this fault, change them. Whether that's new rubber ones for a cheaper fix or F75 kit if the customer is up for it.

I do see what you're saying about looking incompetent, but at least you are actually acting as an engineer and testing rather than just changing all the parts it "could" be at a large cost.

The chances of the pump, pressure sensor, tubes etc all failing at once are very slim. Its usually one of a few things that causes a particular fault. If all need changing it just shows that there is a common cause of the issue. Dirty system. So usually changing the parts will only mean that the fault will re-occur when it gets blocked again.

just my input

Piers

 

[Steelmasons]

There is just one F75 fault!

But it has many possible causes!

Tony is right,

there are many things that can cause the fault, it doesnt mean you have to change every part thats a possible cause... thats just guess work and throwing parts.

Cleaning the sensors can solve the issue, as im led to believe its usually dirt/debris in the pressure sensor causing the issue anyway.

Vaillant offer call outs so its worth ringing them directly if you are concerned over prices etc.

Piers

So are you suggesting I am a parts changer pliers?

When attending these boilers I check the hoses and if solid I change them whether or not f75 has reared its head ,the client is more than happy when they see the black flakes causing the blockage , if the sensor reads pressure when system is empty then I will change sensor , while I'm at it I remove filter and check/ clean , a replacement burner door seal is fitted as a matter of course along with a combustion analysis , obviously the costs are kept to a minimum due to using hoses @ £20 as opposed to the f75 kit @ £150 , 90% of the time the hoses will be choked along with sensor partially blocked/faulty , expansion vessel in most cases will require re-pressurising , I guess you could say the customer got lucky having an engineer attend who knows what he is doing unlike some.

Blocked hoses is NOT caused due to a dirty system , if sensor reads pressure when system is empty then time to change it , as I said in a previous post the pump does not get changed as a matter of course.

Cleaning 'sensors' you say? Is there more than one pressure sensor? , "as I'm led to believe"? , and you feel you are able to give advice on such matters? , jeez.

F75 kit with relocated sensor is a band aid for a parts chucker , I won't go into the reasons as you wouldn't understand.

 

[Steelmasons]

Feel privileged piers with regard to the thanks from agile.

 

[Steelmasons]

The chances of the pump, pressure sensor, tubes etc all failing at once are very slim.

You forgot to mention expansion vessel/canoe filter.

I've attended many vaillants whereby all of the above required attention , only last week I had to change........

Hoses due to being partially blocked.
EV issue.
Filter blocked.
Sensor out of calibration.
Wilo circulator vibrating (main cause of f75).
Rubber burner door seal changed.
Combustion tweaked due to vibration at low modulation.
Boiler was an 831.

Customer wasn't too happy with the previous guy as all he did was remove sensor and clean.

 

[Piers1989]

You're very defensive. I never suggested you are specifically a part changer.

So a "blocked" hose isn't down to dirty systems... What's blocking it then?

I referred to them as sensors in the plural tense because more than one person mentioned them.

I don't know a huge amount about vaillants, I'm simply putting across my view.

I'm sure you're an excellent engineer and you seem to know your stuff

Piers

 

[Terry lambert]

The boiler I worked on last week, you could have drunk the water.

Yet sensor blocked with carp and no doubt hoseswill be too when I change those