vaillant ecomax pro 18 "noisy fan ???"

[jono44]

Hi everyone,

I'm new to your site and I am an rgi although most of my plumbing life has been in Australia. And the many boilers old and new over here leave me scratching my head on occassions.


The problem I've encountered is the above mentioned boiler which is serving an openvented heating/hotwater system had tripped out to a F5 fault code - I've reset the over heat stat inside the boiler and got it going no worries.
The boiler is very noisy whilst working up to temperature - More noisy than I've ever heard one of these boilers. It seems to modulate quite heavily coming upto temperature and then it quietens down to gentle hum.

The customer reckons its slowly been getting worse for the last month or so (called me when it broke) and she likens the noise to a washing machine (but not as loud).
To me (with the covers off) it sounds like a noisy motor or bearing. But it's hard for me to pin point.

MY THEORY is it could be the fan on its way out but I'm not sure because it's as quiet as a mouse at temperature - but that could be because its not working as hard ??
And would the over heat situation have arised from the fan??

The last guy who serviced it (two years ago) wrote in his report he had reset the over heat stat and carried out full service including opening up the heat section, cleaning and replacing the necassary gaskets.

Do these boilers regularly overheat and trip the stat.?

I am going back next week with a gasket kit and will do full service and and recommision to MI standards but I am not sure about the noise and wether i should replace the fan while I'm there.

Any advice from you fellas would be much appreciated and if you'd like any more info let me know.

Many thanks in advance,
Jon Cox.

 

[mickyg]

Heat exchanger is partially blocked. Flush it or change it.

 

[jono44]

Thanks mickyg,
Makes sense -
would the circular heat exchanger give the impression of the noise i suggested and cause the boiler to modulate more intensely? - I think it modulates heavier than it should.

I've flushed heat exchangers and descaled etc but not one of these suckers, is there anything I should know to make the job run smoothly,
ie; extra seals kits or anything in that area, and is it worth giving these type of heat exchanger acid wash.

I'll also suggest customer has a magnaclean cut in.

 

[mickyg]

Normally in this case I'll just carry out a full system powerflush. It should clear the heat exchanger if done well and cure the actual problem at the same time(ie the contaminated system). A machine with reverse flush is very useful in this situation, clears alot quicker.
If you haven't got a pflush machine you could just try some decent chemicals for a couple of days like X800.

 

[jono44]

I chose the gas analyser over the powerflush machine - it all starts to become very expensive - especially when a bloke thinks he might make it back to Aus one day (we don't have central heating).

I get another plumber in the area to do an occasional flush for me around 260 quid - it also starts to add up for customers too.

I see what your saying though - no flush and the problem will return.

 

[Agile]

I dont think he is saying "no flush and the problem will return".

Its a case of no flush and the problem will still be there!

I think your boiler has a heat exchanger which consists of four seperate sets of loops which are all in parallel. The problem with that is any chemical treatment will flow through the clear loops but not through the blocked one(s) to treat them.

Tony

 

[jono44]

What I mean though, is that if I just clean up the heat exchanger the customer will have a quiet and safer boiler for a time. I'll have a happy customer for a time as well.
But that time will be restricted to as long as takes for the heat exchanger to sludge up again.
I imagine the boiler must be only four or five years old and it took this long for the problems to start (or so the customer tells me).
She has already said if the costs become to high for parts etc that she'd just rather have a combi put in - which i think is crasy - yes I can make money but thats not what It's about for me (you can call me crasy too but I don't rip people off).
If i put a combi in she'd have to have a power flush, so I'll just have to convince her that £260 for a pflush and £100 or so for a magnaclean plus my time spent will give her many more years of trouble free happiness with her existing system.

It all starts to add up, but what can you do?
Jon.

 

[mickyg]

the main problem is as Agile has pointed out, its very hard to clean these heat exchangers without a pflush machine. I find that reverse flushing them is the most successful, due to the design of the coil.

 

[jono44]

Thanks fellas,
I'm taking it all in!
Jon.

 

[Agile]

But that time will be restricted to as long as takes for the heat exchanger to sludge up again.

If the system is properly power flushed AND the blocked loops in the boiler are cleared then it will never block again.

Whilst Mick used to work for Vaillant and will have seen a lot of boilers, I have never encountered a blocked HE of that type even though they were used on most boilers made a few years ago.

I must conclude that they are not prone to blocking.

Tony

 

[jono44]

I'd like to thank you guys very much for your input.

I am going to have to power flush - especially on the conclusion i've come to from Mickygs advice.

I was up in the loft and could see that at some stage a heating engineer had dosed the system with inhibitors (because they had left the empty tubes up there).
Although that doesn't tell me that they ever power flushed the whole system in the past, ie; before the modern boiler was installed.

I was wandering if you'd give me your veiws as to whether open vented systems are compatable to modern heat exchangers due to the fact that they are open to atmosphere and have the added risks of taking air in to the system on occasion and are more prone to sludge than a sealed system.

I am still learning and getting my head around the heating systems over here.

Do you think that in a situation like this one or others that it would be best (if practicle) to convert the primary side of the system into to a sealed system.
Also if an old system (open vented) has been upgraded with a new boiler and all was power flushed etc and done properly to the current standards.
Do you think it will stay reasonably clean and sludge free for years and years or would it need a more hands on approach and need regular draining and refreshing of chemicals into the system. ie; annually, biannually or even every five years.
I realise Tony already said he doesn't come across a lot of blocked heat exchangers but I am just trying to refine my opinion on open vented systems.

I only ask these questions because i'm interested in doing the job properly.

Anyones opinion is appreciated.

Thanks again,
Jon.

 

[Agile]

I only said I had not come across a blocked HE OF THAT TYPE !

Have you checked that boiler cab be connected to an open vented system? I think so but its important to be sure.

Open vents are less efficient, more prone to blockages and in theory more reliable. In practice they are less reliable because the users dont bother to top them up!

Putting stickers and empty bottles at an installation is not proof that they have been treated!

Cowboys fit a sticker and sell the product on Ebay less the sticker!

Cowboys also fill the bottles with water and PRETEND to have added the chemical !

If the HE is blocked, the BOILER itself has to be power flushed, including reversing the machine. Citric acid ( DS40 ) is best for that, possibly with a run with DS3 ( sulphonic acid ) if lime scale is suspected.

Tony

 

[gas4you]

These boilers, along with the revamped ecotec Plus 400 series are a PITA for HE's blocking.

Saying that so are most of the Ecotec Plus series.

Had loads where I have had to flush just the HE to get them going again. I hate the job

 

[Agile]

Dave, I hope that those blocked HEs were not ones which you had fitted !

Perhaps I have just been lucky not to have encountered even one from any manufacturer !

Tony

 

[gas4you]

I think the problem is that any heat only boiler with a Giannoni crap HE will suffer from the slightest crap left in the system, as the HE just acts as a sump.

It takes very, very little to cause noise problems in the Vaillants.

We have to remember that power flushing will only get a system about 80-90% clean on a good day.