Ariston Micro Genus heating problem

[barneytravolta]

I have an arison micro genus II 31 MFFI combi boiler and im having problems with the C/H, the heating only heats up to 46'C on the display on the front of the boiler then cuts out, once it drops back down to about 40/41'C the burner then fires back up and repeats itself once it reaches 46'C again. i've tried changing the temp sensor on the flow pipe from the heat exchange for the one on the return pipe, but still the same.
the boiler is not reporting any faults and the problem is not present on the DHW side.

Any ideas????

Thanks

 

[croydoncorgi]

If the HW preformance is OK, it sounds like you've got major issues with CH flow. For some reason there isn't any! As a result, the boiler is cycling on and off on the overheat limiter because the hot flow never makes it as far as the sensor before the water in the heat exchanger hits the limit (about 86 degrees ISTR). Maybe the return filter (if any) is blocked...?

 

[PEDANTICVINDICTIVEMAN]

Whats it like on the fast spin cycle and dont forget to use Daz for whiter whites.

 

[ChrisR]

IS IT ok on HW?
At one of the other 17 eurocombis today which did it on CH and similar on HW, unless you put it in what I assume was a maintenance mode, whereupon it burns at full gas pressure, so everything gets jolly hot. There seems to be ONLY a ch sensor. Has me guessing!

 

[kevplumb]

hello stranger

 

[weargas]

stuck in dhw?

 

[barneytravolta]

yeah its fine in dhw mode, but just dont work in ch mode. ill try a bleed out and look for a return filter of some sort. cheers for the comments (those with sensible ones) unlike the penis who posted the comment about fast spin and peeing in tanks.

 

[kevplumb]

ooooooh

handbags at 10 paces ped

you ped are a cad and this poster demands satisfaction

 

[PEDANTICVINDICTIVEMAN]

ha ha ha ha ha ha ha ha ha, pead my pants laughing, will go and put them in my Bottywarm condensing washing machine on rip off cycle.

 

[kevplumb]

its a joke isnt it we take all the ****e and are not allowed a blowout occasionally *******s Will this cure heavy banging wheezing bubbling, I was under the impression this was a preventative / small solution.

 

[MickaelDzz]

I have exactly the same problem now:
Even if I put the central heating switch up to the max, the boiler fires and heats the water up to 45degC and then stops and waits until the temperature drops down to 39degC and then restarts. THis repeats over and over again...

I fitted a new refurbished PCB (as the previous one had developped the A01 error) a few month ago and this is the first time I am using the heating since then. I have also fitted some new rads and did a few few other things since then. Not sure whether this is related though...

Suggestions would be appreciated!

 

[Gasguru]

The spindles on the temperature control knobs are often inserted incorrectly.

You may find the heating potentiometer (the preset on the pcb) is not being sufficiently rotated to give a maximum temperature setting.

Have a look and it becomes obvious...take care when reassembling the board casing...it's easy to mis-align a spindle and break a preset (seen others do it) and the casing fixing points often snap

 

[MickaelDzz]

Thanks Gasguru!

I have checked the spindles and they are ok.

I have also done a few trials with the max heating power potentiometer but the result is always the same. Temperature goes up to 45degC, burning stops, temp goes down to 39, burning restarts...

I bled all the rads and they all get warm (but not hot)... so I guess this rules out an issue with the flow in the circuit.

Any suggestions?

 

[barber]

I got the same fault on exactly same boiler at the moment. I think it is the pcb and I am changing it soon. Will let you know how i get on

 

[barber]

Changed board today and all sorted. Never come across that fault before but will remember it now. Change the board if you haven't already. Good luck