Ariston Microgenius 32HE

[tanker]

Hey,

I have an Ariston Microgenius 32HE combi boiler that seems to be having oddly, I’m not sure if I might have done something to cause the problem. Just over a week ago I noticed that water was dripping rapidly from the discharge pipe. Investigating further I changed the DHW exchanger, having realised that it must have sprung a leak. Changing this component proved relatively easy other then not being able to place the orange cover onto the new exchanger once in position.

I’ve had a week of trouble free heat and hot water until yesterday. I noticed after turning on and then off a hot water tap in the property that instead of shutting down the fan and pump continue to run continually. One to two minutes later the pump stops, the fan then continues for a further few minutes.

Additionally sometimes in addition to the above occurring the boiler will relight temporarily after turning off the water at any hot outlet. When the boiler relights itself it lasts for seconds (with the pump and fan running as mentioned above). No hot water is being drawn at this stage, nor is the heating set to ‘on’ on my programmer.

In case it helps the LCD displays ‘ON’ when the fan and pump run, when the boiler lights itself for the couple of seconds the LCD displays the temperature of the water, the hot water LED is light at this stage.

Finally, if the heating is on and there is a demand for heat then when using the hot water the above does not seem to happen, instead after the turning off the hot outlet the boiler resumes with the central heating within a few seconds.

Although I was happy to replace the DHW exchanger I would be unwilling to mess with anything relating to gas. Before I call in a CORGI guy I would be grateful if any of you experienced folk could tell me whether or not I might have disturbed anything that might have resulted in this problem. I’m pretty good at tracing faults if I have something to go on!

Many thanks in advance,

Tank

 

[tanker]

Guys,

Not sure if any of you would have had an idea about what caused the above problem but I had an engineer out yesterday. He told me that it appears that I need both a new PCB and fan for my boiler. Would this make sense. The boiler is only just over 12 months old and it sounds like it's going to be expensive

Tank

 

[Agile]

I would have thought the boiler might have had a two year warrantee.

Firstly you need to make sure there is no hot water flowing throung the boiler by turning off the water inlet isolator.

Otherwise I would have expected the operation is a DHW preheat followed by a pump and fan over run, that is normal operation.

Without reading the instructions, I cannot confirm that but its what I would expect!

Tony

 

[ChrisR]

the boiler will relight temporarily after turning off the water at any hot outlet.

That bit is likely to be due to some air being trapped in the tap water pipes somewhere. It acts like a spring so the water bounces and confuddles the boiler. ANy taps you don't use much, anywhere? Try running all, hot and cold, one at a time, for 30 seconds at full rate. Includes the garden tap.

Boilers often have overrun timers on the pump, to dissipate any excess heat. That would account for the pump staying on, but I doubt the fan should stay. It probably isn't fully explained in the manual, so it might be worth calling Ariston. They might be a bit anal and ask for a COrgi number - give them a 6 figure number starting with a 1. I'll delete that in a day or so!
I'd be surprised it it would need both a pcb and a fan.

I'd be interested to know what this turns out to be.

 

[tanker]

Cheers Chris,

I've not got any taps that I haven't since opened, however what I didn't mention was that I did install a pressure reducing valve at the same time.

Could this have anything to do with it???? Just in case I will try what you suggest running all taps and see if this helps!

I'll keep you informed.

Tank