Ariston Micro Genus HE32 MFFI pressure problem

[britishrallying]

Hi,

Ive had the above boiler for a few years now and had an ongoing issue with it. The condensation trap keeps filling with water, CH goes off until you've empty half out then reset it. Ive noticed this week though the pressure falls to 0 and the trap is totally full. The pressure seems to drop when the combi is not running?

The heating dial is set to 3 so not as if its on full chat.

Any help appreciated,

Gareth

 

[britishrallying]

Can anyone help?

Gaz

 

[Gasguru]

The trap is supposed to have water in it to prevent flue gasses escaping.

How is the boilers flexible condense pipe installed onto the main condense pipework? There should be an air break. ie the flexible hose just sits in a 32 or 40 waste pipe allowing air to enter the pipe and backflowing water to overflow. Perhaps your waste pipework is partially blocked and the water is backing up. A photo would be useful.

As for the pressure it should be about 1 to 1.5 Bar with the boiler OFF and the radiators COLD.

On the early models there was a design fault with the recuperator heat exchanger. The boiler will show a fault error due to condensate backing up in the heat exchanger since it could not drain fully. Most would be fixed under warranrty though.

 

[frankthegasman]

the two thing you descibe are not connected to each other,if the condense water does not get away the drain is blocked this would stop the boiler working,but it is probably because you have not got water in the system you should have 1 bar on the pressure gauge to start check out side to see if the prv pipe is leaking into the garden if so the pressure vessel has probably run out of air and need 1.5 bar of air in it good luck

 

[Gasguru]

The pressure vessel has probably run out of air and need 1.5 bar of air in it good luck

No no no about 0.7 bar is ample for the expansion vessel pre charge with a standard height property even with the boiler in the basement.

Setting the pre charge higher than necessary reduces the effective capacity of the vessel and the system pressure may rise un-necessarily high.

 

[britishrallying]

Hi Guys,

I know there suppose to be water in it, about a 1/3 or something like that, but its full to the brim, empty some out then the next day or in some cases 5 minutes later its full again. But now every time the boiler comes up with the fault code E02 water trap is full, the pressure has dropped to zero!

This seems a bit strange to me, why the pressure would drop off when the trap is full. Today havent had the heating on and the pressure has stayed at 1.4 bar all day so rules out a leak, ive only got a two bed terraced with 6 rads and know where all the pipes run, only got installed a few years ago. Checked for leaks and nothing.

How is the boilers flexible condense pipe installed onto the main condense pipework?

I take it this is what runs from the boiler to outside? if so it seems to be fitted into a 20mm piece of conduit, dont think theres an air gap, pipe doesnt appear to be blocked. Actually just had a close look and the grey flexi pipe from the boiler sits in a loose piece of placcy conduit before recing down to 20 mm piece:

http://www.britishrallying.com/images/PICT0011.jpg
http://www.britishrallying.com/images/PICT0012.jpg

Ive had this prob since really having the boiler fitted, only happens when heating on, hot water fine! Had the boiler serviced in December by the chap who fitted it and explained the prob to him but he coulnt find anything wrong other than a moth in the boiler

Any thoughts?

Gaz

 

[numpty1]

different boiler aco mffi32 has had a similar prob,found the main heat ex leaked when hot,and ran into the condence pipe.pressure stayed up when left off.

 

[ironmike]

Aristons, wonderful boilers.

 

[britishrallying]

Hi,

Sorry its the Ariston 28 mffi.

Will give the plumber a call tomorrow to get it checked out.

Cheers guys

Gaz

 

[britishrallying]

Oh well I found the problem with the pressure!!

I had a leak!! luckily caught it in time before any major damage to the ceiling. It was a 22mm t piece reduced down to 10mm that was leaking, when inspecting it looks as though the solder hadnt taken all round the joint. Replaced with a new t piece and reducer and alls well.

But the condensation trap is still filling up! bugger

Gaz
www.britishrallying.com

 

[bengasman]

It really is a problem with the condensate pipe coming from the trap, not the boiler itself that is faulty

 

[frankthegasman]

sorry air in vessel is .7 bar air. 1to1.5 bar water pressure,vessel holds 7 litres of water sorry for previous wrong pressure ,good luck

 

[britishrallying]

It really is a problem with the condensate pipe coming from the trap, not the boiler itself that is faulty

Is this the plastic pipe that goes outside? Will strip it down the weekend and have a look see if its blocked etc!

Gaz

 

[bengasman]

no need to strip it down.
just undo it near the boiler and poor 2 litres of water in the pipe.
one could argue that you have to be corgi registered to do this