Central heating problem

[rockinter]

Well, I had a brand new Vaillant Ecotec Plus 831 boiler fitted 3 years by a corgi registered person after my old boiler had its days after 15 years.

Since that day I have had nothing but trouble with the boiler.

After 4 weeks of fitting the boiler it started to make a lot noise, then temperature on the boiler should it went to 74C then cut off. It then bought up an error of f23.

We rang up Vaillant as it was under guarantee. The Vaillant engineer came and said the secondary heat exchanger had blocked up because the system has not been flushed properly. The engineer opened up the boiler and cleaned out the heat exchanger in front of us. It had black bits in the 2 holes which are linked to the radiator system.

So we then rang the person who fitted the boiler. He firstly denied it was his fault. Saying he had already powerflushed the system when fitting the boiler. We got the manufacturer to ring him. He then rang us back saying he would do a powerflush a second time but after that if anything happened it would not be his fault.

So the boiler person came and powerflushed the system, he spent the whole day doing it. Going to each radiator turning the valves on and off.
Then after 2 weeks the boiler started to do the same thing as before stopped working. So we got some other plumbers to give their opinion.

One said fit a Magnaclean. So we fitted a Magnaclean. But still the boiler had same trouble of heat exchanger getting blocked.

Another plumber said fit a Y strainer. So we fitted a Y strainer. Still we had the same trouble.

Another plumber said fit Auto valves on the highest points, so you don’t have air in the system. We did that but still had the same trouble.

We then rang Vaillant to say that we are still having the problem. The engineer came back, showed us the black bits coming out of the heat exchanger. He said one of radiators must be corroding that is why the stuff keeps coming.

So then we changed all the radiators. And now still we have the same problem and also the guarantee has finished so i can’t go back to the manufacturer. It has just become one big headache. I feel like throwing the boiler out.

Some more information:
I contacted magnaclean, and there system doesn’t seem to capture all the magnetic bits because the water comes in at such high pressure and they are so small. Also the y strainer doesn’t capture the bits as they are so small. It seems the secondary heat exchanger collects all the small bits and they become big bits and block up the heat exchanger. The bits are magnetic, I tried it with a magnet.

Over the 3 years i have put the following cleaning agents and inhibitors into the radiator system to solve the problem but none of them worked fernox f3 cleaner, fernox f3 superconcentrate central heating cleaner, fernox f1 superconcentrate central heating protector, Sentinel x400, Sentinel x100, B&Q cleaner, B&Q inhibitor.

Once the pressure is filled in the radiator system it doesn’t lose pressure.
The bits in heat exchanger are big black and magnetic. The bits on the magnaclean are fine soot like.

So has anyone got any solutions to why this is happening and what is the solution?

I really need your help!

 

[doitmyself]

I had a brand new Vaillant Ecotec Plus 831 boiler fitted

That's a combi boiler

It then bought up an error of f23.

That means: Water shortage, temperature difference between flow and return NTC too large. The cause: Pump blocked or defective, pump output too low, flow and return NTC interchanged.

The Vaillant engineer came and said the secondary heat exchanger had blocked up

Do you mean the plate heat exchanger (rectangular box) for the Hot Water system or the main heat exchanger (big round thing at top of boiler)?

So the boiler person came and powerflushed the system, he spent the whole day doing it. Going to each radiator turning the valves on and off.

On the face of it, he did the job properly.

 

[rockinter]

i mean the heat plate exchanger

 

[migoplumber]

do you possibly have any iron pipework in the system, connected directly to any copperwork?
also can you make clear if the radiator system is vented or sealed?

 

[rockinter]

All the pipes i can see are copper. The system is sealed.

 

[danielp]

well be pointless putting auto air vent on then , can you get him to drain the system from boiler clearing all muck in pipes above and possibly boiler aqnd then connect a flusher to the flow and return pipes that should surely sort it ?

 

[rockinter]

i guess i could connect a power flusher. But i am thinking is it worth it considering the installer has done it twice already?
Also if i fit it to the flow and return pipe wouldn't that leave out the boiler?

 

[stevetheplumber]

we had a similar problem with a vaillant despite powerflushing it we solved it by putting 3 gallons of flushing agent into the system running it for a week and totally reflushing with a better machine with a mag filter on it

 

[rockinter]

which flushing agent did you use?

 

[danielp]

no connect to the boiler side and flush boiler

 

[rockinter]

Just had a reply by someone and they said the following
"This the typical problem which has happened to quite a few people,the fault lays in the poxy heat exchanger.
It is made by by gionnoni and at certain points it has clearances of 5mm as well being dual pass
Even the slightest amount debris will block this up and once in it is very hard to shift,we have one in the garage which is blocked solid and changed great cost to the customer,The manufacturers know about it but will always blame the installer normally one man band and whole weight of massive organistaion on his back.
The twits at ginnoni have now redesigned it remarkably similiar to another boiler manufacturer who hold patent to their HE which is alot better,thats why they warranty it for 10 years
what i would suggest is first remove the cause of the magnetite and then ask the installer to flush just the heat exchanger by cutting into the flow and return ,personally use small descaleing pump for this type of work and hope it gets rid of the problem "
Anyone heard of this?

 

[Bernie2]

Sounds reasonable to suspect heat exchanger restriction.

But where is the magnetite, if it is magnetite, coming from in the first place?

Did the power flush clean the system properly?

Magnetite as you probably know, is a sign of corrosion. Of what though? If your pipes are okay and your rads are new what then?

Basically it only probably leaves the boiler and if the heat exchanger blocks up with such a small amount of scale, which may be the systems natural corrosion after a refill, then it would seem to be an on going problem, even if you flushed it properly and who is to say it hasn't been flushed properly?

The thing is the boiler is fairly new on the market and a bit to early to guess at what may be wrong or whether the fault, if it has a fault, is a type fault or a model fault.

All you can really do is as others have suggested, flush and try again. If you feel the heat exchanger is faulty and can get a better replacement then I would do that if it was me.

 

[JD24HOURS]

hi i had the same problem with a vokeras and in the end the manufacter fitted a biger plate heat exchanger which sorted it but not after a lot of agro

hi i had the same problem with a vokeras and in the end the manufacter fitted a bigger plate heat exchanger which sorted it but not after a lot of agro

 

[charlie frederi]

do you possibly have any iron pipework in the system, connected directly to any copperwork?
also can you make clear if the radiator system is vented or sealed?

Take it as its a combi boiler must be a sealed system

 

[migoplumber]

charlie many combi's can be run tank fed on ch side - some can also manage it on the cold.

 

[charlie frederi]

charlie many combi's can be run tank fed on ch side - some can also manage it on the cold.

Oh right never seen that myself and been plumber heating/engineer for 25 years

 

[charlie frederi]

charlie many combi's can be run tank fed on ch side - some can also manage it on the cold.

yes but they are still sealed systems not vented as there is no open vent
to the header and cold feed has a non return valve fitted with a stopcock so it still relies on the safety valve
the term is low pressure sealed system that is why i said i have never seen a vented system on a combi

 

[benny_headland]

hi guys im only a secound year apprentice but im quite sure your not supose to conect a power flush to the boiler and only the flow and returns as it can couse problems with the boiler! as it has obviously

 

[JD24HOURS]

go back to valiant and tell them it is there problem because if everything has been done properly then may be the plate heat exchanger is just to fine and causeing the problem we had the same prob with vokera and after 2 years they just replaced the boiler and we never had the problem again

 

[charitynjw]

"One said fit a Magnaclean. So we fitted a Magnaclean. But still the boiler had same trouble of heat exchanger getting blocked."

Is it fitted on the return pipe?

 

[rickphysicist]

I am not a plumber but have been called in by my son whose plumbers have failed to solve a problem which sounds much like this. The boiler effectively shuts down through water starvation.

I notice two irregularities on the installation - Vaillant vented ecotech plus (inst. guide). One, the pump is in the return pipe before the boiler and drives through a raised loop with no bleed, Two, the feed and vent are within 150mm in the flow circuit but the wrong way round.

Number one exacerbates the problem but I am sure when we swap them round two will be the real cause.

When air/water mix flows down the flow circuit, the first opportunity the air gets to escape is the water feed pipe (15mm). It takes it, the bubbles expand rapidly as they move up the pipe, so reducing the system head throughout the system but especially at the junction with the flow pipe. This means more of the air will follow the initial bubble and none will move on to the vent pipe. The water head in the vent will be lowered and could even allow more air in that way. Water will certainly be expelled from the circuit and it's recharging will be obstructed by the counter flow of air - this is a 15mm pipe. Add to that the potential for further air input through bleed valves - depending on position - and one can see an escalating problem. That is what I think we are seeing and I hope to fix it soon.

 

[mrclemo]

you still have sludge in the system from a proper powerflush not being done. The magnaclean will clean the system but over a period of time. What you need to thoroughly clean the system you want a powerflush with the magnaclean filters on it, also the engineer needs to go round each rad with an agitator on a cordless drill and bang the rads to get every bit of sludge out.

 

[FD Powerflow]

You could try fitting a TF1 or Magnaclean twintech as these combine magnetic and non magnetic particle removal so you get magnetite and any other debris out of the system. I would also recommend getting a System Health Check from a plumbing merchants such as Plumb Center or PTS, these are made by Fernox and are also what Vaillant use to indentify potential faults with system water, this will identify if there is enough inhibitor present, what type, if there are high levels of flux/calcium carbonate/iron/copper etc and also recommend a course of action.

It might help to post the results of the system health check on here too.

Happy hunting

 

[thomas donovan]

we get a bit of wood wrapped in a rag and batter the sludge out of the rads with a hammer, sounds iffy but works a treat