F75 Vaillant ecto tech 350f, Plumbing or Boiler Fault

[Delphine]

Hello, I had a new Vaillant ECO TEC PLUS 831 installed in April, since October it has broken 4x with a F75 code. FAULT PUMP/WATER SHORTAGE
The boiler is still under guarantee another 9 years and the plumber/installers work is also, but i have no written confirmation of that.
The problem is, the plumber will not respond to any of my calls and messages any more and i have been without hot water and heating for a week. He has always been incredibly unreliable, not showing up when he's said without informing me etc after the initial installation.
If it is a boiler issue Vaillant will fix the boiler for free, however they won't touch a plumbing issue and i would have to pay a £90 call out charge then for nothing.
So i don't know whether to risk calling out Vaillant or call a different plumber. As i don't know where the problem lies.
Old boiler, no plumbing/pressure problems but needed replacing after 15 years, had tank in attic.
So far, with this Vaillant first fault was F28 - ignition, water pressure was low, taps were turned to re-pressurize. Had a leaking Rad, plumber put radiator sealant to temporarily seal it before rad was changed. (he didn't turn up to do this) But leak is still holding.
F75 x4 faults
F75 First time, turned boiler taps no water was being let into the system. Plumber came after a week, did something. Fixed for 2 weeks.
F75 - I turned boiler taps (probably the wrong thing to do), boiler leaked quite a bit. Plumber came leak on boiler stopped, worked 2 weeks.
F75 fixed, broke within 2 hours of plumber leaving.
F75 current problem
The water pressure in the Sink taps is good with and without the extra/external electric pump. Hot water not as good when bath runs without pump.

Pressure on hand held monitor and boiler reads 2.7 now. With the F28 the boiler read 2.7 on both too, however the actual pressure was bellow 1 apparently. I realize this is quite high but the plumber said that this high reading was OK, and that the devices weren't communicating a correct pressure.
While the boiler was working, the pressure used to read 3. It never let out the "bang" pressure over flow.

I do not have any other information I'm afraid. I can only assume if it was a boiler problem the plumber would have left it to Valiant? or not... who knows.
So two questions, is it likely to be a plumbing or boiler problem? As in who do we call?
Also is there anything that can be done about the unreliable plumber? Because calling a different one will incur fresh costs.
Many thanks in advance for any information and help.

 

[simond]

Fresh costs inevitable, because your original bloke won't come back.

I'll be honest and say that your description is a bit of a ramble and I can't understand what is going on. No idea what the external electric pump is doing but this doesn't sound good.

I think you are either going to have to edit the story so it makes sense (for instance, when you mention taps, are you referring to those underneath the boiler to fill it up, or a sink?), or pay someone else to cast their eye over it.

This is a lesson to those who get n quotes and assume that if the boiler is the same they can choose the most reasonable bidder. Gas Safe registration is not a guarantee of good workmanship; saw two new boilers yesterday, total lousy installations, both Vaillants, both customers have paid £94 only to be told the installer was a buffoon and a whole pile of remedial work needed.

 

[Delphine]

Hello, Ah good point re taps.

External pump as in the pump that increases pressure to showers etc, not necessary for boiler to function.
Taps SINK Taps "The water pressure in the taps is good with and without the extra/external electric pump. Hot water not as good without pump"
F75 bit i mean valve taps on boiler

As i mentioned, Vaillant will take care of boiler malfunctions but not plumbing errors, so i'm trying to determine what the F75 code could relate to.
And if there is anything that can be done, re either shoddy work on the plumbers behalf (although i cannot verify that yet) or get him to oblige to fix the fault.
Thank you

 

[simond]

F75 could mean a number of things to do with flat expansion vessel, duff pump, faulty pressure sensor, blocked filter. All related to a pressure transducer inside not being able to detect a small blip in the water when the pump starts (the boiler pump).

You will really need someone to look at it. Whether you can get the installer back is down to you, a good indication is to look in the back of the Vaillant instructions and see if the 'benchmark' form is fully complete, and whether you received a gas safe notification in the post soon after the boiler was installed. If neither of these things happened, you definitely have had a rogue.

What is the make and model of the hot water pump, by the way?

 

[Delphine]

Thanks for assisting me, what you mentioned seems like it would be to do with the boiler rather than the plumbing, or have i misunderstood? Does that mean it would be wise to call a vaillant engineer for free or a plumber in a light opinion?
I have at the back of the manual a page called Gas Boiler system commissioning checklist which is pretty much filled in and signed, but nothing came through the post. Only the actual boiler warranty.
Here is a picture of the specs of the pump, it's noisy and was second hand but seemed to function well.

 

[Delphine]

Thanks for assisting me, what you mentioned seems like it would be to do with the boiler rather than the plumbing, or have i misunderstood? Does that mean it would be wise to call a vaillant engineer for free or a plumber in a light opinion?
I have at the back of the manual a page called Gas Boiler system commissioning checklist which is pretty much filled in and signed, but nothing came through the post. Only the actual boiler warranty.
Here is a picture of the specs of the pump, it's noisy but seemed to function well.

 

[simond]

What model of ecoTEC? Will begin with 4,6,8 or 9.

 

[Agile]

You have not properly told us what boiler you have.

I am going to guess that its a heat only boiler and that you also have a hot water cylinder ( hence the pump ).

I am seriously worried that you have an uncleaned and so dirty system. Rad becomes holed and leaks, leaks in boiler etc.

Usually I charge about £740 to fit a heat only boiler and that includes properly cleaning it. Was your much cheaper than that? How long did it take him? How did you choose him? Was he the cheapest?

My expectation is that its most likely to be caused by dirt based on what you have said and that the electronic pressure transducer is partly blocked. You should only need to top up pressure every 3-6 months.

So a GOOD local boiler engineer would be my suggestion.

BUT your installer should really be dealing with these issues. I always wonder why people employ these types who ignore you once they have been paid. Where abouts are you?

Tony

 

[TCCHeating]

You should only need to top up pressure every 3-6 months.

Where did you pull that one from Tony?

I haven't topped the pressure up in my sealed system for 3 years. And it's still holding exactly the same as it was 3 years ago. I would certainly prefer my watertight system to one that needs topping up every 3 months

I know what you are trying to say! But you could have put it better mate

 

[Delphine]

Vaillant ECO TEC PLUS 831

It wasn't on the cheap side of the price range at all. He was picked because he seemed reliable! accredited and local-ish.
I believe the whole system was drained and cleaned in April on installation. Took about a day. Including removal of old boiler and tank. This is a combi boiler.

 

[TCCHeating]

Vaillant ECO TEC PLUS 831

It wasn't on the cheap side of the price range at all. He was picked because he seemed reliable! accredited and local-ish.
I believe the whole system was drained and cleaned in April on installation. Took about a day. Including removal of old boiler and tank. This is a combi boiler.

That's worrying. I hope that you still have a hot water cylinder with that shower pump??? You can install a combi and still keep the gravity cylinder. Can even use the combi to supply some outlets and cylinder to supply others if you split the system But I very much doubt this in your case

 

[simond]

So many things wrong. Remove water pump, you could catch a terrible disease from the water and/or be prosecuted. You are putting other nearby properties at risk too.

The installer should be locked up frankly.

 

[simond]

Took a day. That says everything. Did he have time to feed his horse?

 

[Delphine]

Hi thanks for your messages, but can we please divert back to the original subject. If the F75 FAULT PUMP/WATER SHORTAGE fault is likely to be a plumbing or boiler fault?
I think the mention of the shower pump has confused the situation, please forget the shower pump. Only the integrated boiler pump Thank you

 

[TCCHeating]

Hi thanks for your messages, but can we please divert back to the original subject. If the F75 FAULT PUMP/WATER SHORTAGE fault is likely to be a plumbing or boiler fault?
I think the mention of the shower pump has confused the situation, please forget the shower pump. Only the integrated boiler pump Thank you

Never mind the f75. What you have posted points to a more urgent problem. Is that shower pump connected to the mains pressure from your combi boiler??