Saunier Duval Micro Accumulator Vessel

[Teapot]

Sons combi is a Saunier Duval F30E plus, ( yes I know what you will all say from reading through the forum ) and is 3 years old.

The fault is a leak on the secondary circuit, domestic hot water.

I have traced the leak to the Micro Accumulator.

The leak appears to be from the area of the bolted joint between the upper and lower moulded sections of the accumulator.

I am a retired motor engineer and was able to use my old endoscope to have a look around and see water in the area of the joint, but due to restricted access could not actually see the exact spot where water was leaking from. There is no leak from the heating element joint on the top of the vessel.

I am presuming therefore that the leak is down to the failure of the joint gasket / o ring, my questions are,

1) is this a common fault.

2) am I correct in presuming the joint / gasket to be the fault, the only other thing I could think of would be a split in the vessel.

3) do you know if the gasket, if that is the fault, is a serviceable item / obtainable part , or as in my old trade, it will be a complete Micro unit.

Hope I have given you enough info.

Thanks in anticipation for your help.

I only found your site tonight, what a great idea.

Hope to be able to spread some of my knowlege and give some help in the cars section in the future.

Regards.

Bill

 

[Dan Robinson]

As you have read Saunier Duval just is a common fault... something the Frenchies sprung on us in a wine fueled flurry of vengence of our superior culinery abilities.

I think your greater worry is the fact that the boiler has to come off the wall to change/repair this part - and seeing as its Sauny that would be a good time to be humane for both you and your sone;and his boiler and it to sleep...

IMHO of couse....:

20.37 Micro accumulator vessel, refer to
diagram 20.26.
Before starting refer to the front of Section 20 Important
information.
For this operation the boiler must be removed from the wall.
• IMPORTANT: With regards to the manual handling operations,
1992 regulations, the following operation exceeds the
recommended weight for one man lift.
• Remove the front panel, refer to Section 17.3.
• Drain down the boiler and hot water ,refer to relevant parts
of diagram 20.1.
Note: It is not necessary to drain down entire heating system to
carry out this work.
• Disconnect the flue system.
• Disconnect the boiler pipes.
• Disconnect the pressure relief valve discharge pipes.
• Disconnect the mains cable and any external controls cables.
• Lift up to remove the boiler from the wall.
• From the rear of the boiler.
• Disconnect the inline electrical connection plug to the micro
accumulator vessel thermistor.
• Remove the slotted metal clips to disconnect pipes from the
bottom of the micro accumulator vessel. Note: Take care there
will be a loss of water.
• Remove the right hand side panel, refer to Section 17.6.
• Bend back securing tab to release vessel from boiler frame.
• Remove the vessel from the boiler, taking care not to strain
the heating element electrical cable.
• Pull out slotted metal clip and pull to remove heating element
from micro accumulator vessel.

I hope or your sake I am wrong, or someone else here knows of another way!

 

[Agile]

Note: It is not necessary to drain down entire heating system to carry out this work.

Phew, thats a relief!

Bearing in mind that its a Sonya Duval and the leak is only mains water then a bucket underneath might be a much quicker solution.

In view of the amount of work involved in dealing with such a minor problem then I do have to say that in view of the lower reliability of that make I would suggest that replacing with another make might be a much better medium term solution.

However, if this retired motor engineer really wants to take on something like this then thats up to him. I think his time would be better spent replacing the wishbones on my Astra though.

Tony

 

[corgiman]

I have to do one of these next week on a glowworm 35 cxi (I think) buts its a SD

thanks for the info dan

mind you when i drained the boiler down the water was as black as your hat, so much for the final flush

 

[Teapot]

Cheers to Dan,

Appreciate the French aspect, having worked on Renault, Citroen, Peugeot vehicles over the years.

I thought their idiosynchrosies were due to them still being p***ed off at losing at Agincourt though

Thanks also for your forsight in posting the notes from page 53 of the manual, I had these to hand already, ( I have given many an apprentice a toe up the a**e for not checking the workshop manual before getting involved ) and had no intention of doing the same. Though how many people in all walks of life, actually fully read manuals ?

Reason for my post was that in my walk of life, and yours I presume, workarounds are often found by the guys with the dirty hands, not the manufacturers or their techies.

Micro vessel is approx. £320 inc. vat. so as you imply, even though only 3 years old this money would be better put to a new, obviously more efficient condensing boiler.

I presume you, and others often wonder, as I did with cars, how the manufacturers come up with the crazy prices for blow moulded plastics, look at the price of B.M. W. and Jag plastic expansion bottles!

..........................................................................................................

Ta Tony (Agile )

Better than a bucket ( in my way of thinking ) would be to isolate the Micro, join the inlet - outlet, disconnect the Micro heating element, bingo problem soved.

Advantage....... no water leak, £320 + saved for vessel £xxx saved on keeping the vessel heated 360 days per year.

Disadvantage.... wait a bit longer for the hot water at the taps

As to wishbones on your Astra, a doddle, piece of the proverbial, apprentice job, not so Jag, B.M.W. and some of the new Audies.

..........................................................................................................

Thanks to all again for your info.

Bill

 

[Agile]

As to wishbones on your Astra, a doddle, piece of the proverbial, apprentice job, not so Jag, B.M.W. and some of the new Audies.
Bill

But do I need a spring compresser just to change the wishbones?

As far as your boiler mod is concerned that would probably be fine as long as you can bodge something. Whilst I can do that kind of thing with a proper boiler with copper/brass bits it becomes very difficult doing it with just bits of plastic.

Tony

 

[Dan Robinson]

Hydraulically disconnecting the accumulator might be a solution for the leak (not that I would like to comment); but what of the thermister? The boiler will be expecting readings.


I have a 206 2.0l HDi, that needed a rebuild of the top half of the engine a few years ago, great drive, but maintenance is awful. Bloody Frogs!

Nice cheese though .

 

[Agile]

I have a 206 2.0l HDi, that needed a rebuild of the top half of the engine a few years ago, great drive, but maintenance is awful. b****y Frogs!

There was this fellow with a 206 turbodiesel just a few years old which had a faulty EMU but the price of that was a touch under £1000 and it was just not worth getting a new one fitted when the local dealership could not guaranty that a new EMU would actually cure the engine fault.

My simple view of vehicles cannot understand why a diesel needs an EMU anyway although they do incorporate the system security.

Tony

 

[Gasguru]

Tony modern diesels are a world away than the old mechanical systems, piezo injectors now operate at 2000 bar

Had a similar scenario on my Kangoo, every so often it would belch out smoke and run rough. Two dealers had it but couldn't diagnose the fault but though it may be the injection pump at £1100. No gurantees it would fix the problem.

Phoned Watson diesel in Wimbledon....diagnosed fault over the phone and not uncommon. Replaced the £100 solenoid valve while I waited and just a 1/2 hour labour cost. Proper service.

 

[Agile]

Thats what I like to do, diagnose the problem on a boiler after the manufacturer has failed!

Its often so easy!

So are some of the earlier security devices! I once drove home with the diesel solenoid powered directly from the battery after the security device had failed. All the immobiliser did was depower the solenoid!

Tony