Ariston Combi Boiler - HW switches off after 15sec, CH - OK

[DimitriAB]

Hi,

have a warm new year everyone, it seems I will be having a not so warm one.

I have a Ariston Micro Genus II combi boiler in the flat. Today I noticed that there is a problem: When taking a shower, the water was hot for around first 15-20 sec, then it becomes cold and does not heat any more.

What happens with the boiler meanwhile - the HW light switches on as normal (showing it is heating HW), the temperature dial shows 99 (Not E99, also not sure what does it normally show), the flame dissapears in 15-20 seconds, leaving the HW light on with the temperature dial still showing 99.

(So I guess boiler thinks the water is 99 degrees C hot and thus stops heating.)

Any suggestions what this might be?

Dimitri

Untitled

• DimitriAB
• 31 Dec 2011
• 1

 

[DimitriAB]

The pressure dial shows 0.85.

0-0.5 Red
0.5 - 1.5 Blue
1.5 - 4.0 Black

 

[BARNY78BG]

plate heat exchanger blocking

 

[DimitriAB]

Nah, was a thermistor. Exactly as i thought. I diagnosed, local gas guy installed. All ok

 

[BARNY78BG]

sorry mate, miss read your thread, thought you meant it was cycling on hot water demand, but hey who needs us when you can diagnose with the power of mind and then tell an rgi what to fix\!!!!!!!!!!!!!! it must be the new age of technical know how..... i am astounded!!!!!!

 

[DimitriAB]

Matey, boiler is not a rocket science. Its all simple physics, i can read online, read user and repair manuals, parts lists ad think. I called a gas "engineer" to diagnose this and he said the same. But i still kind of need a qualified person to do such a rocket science operation just because he is corgi registered. Switch off, close vents, drain, unscrew part, replace, fit new part, refill, and take £70 thank you for 15 min work.

 

[BARNY78BG]

mad then isn't it that so many of us gas engineers have wasted so much time and money doing what we have done to get where we are!!!!!!!
we should all follow in your footsteps, cos its not rocket science is it, anyone can sort it if they can read and copy what they see!!!! forget get about how boilers work and just assume cos it seems likley, your words are an insult to every RGI on here, dont let your horse trample the flowers!!!

 

[mcmoby69]

Matey, boiler is not a rocket science. .

nah, but when you do get it wrong, it could go off with a ****ing big bang!

 

[DimitriAB]

Cool story bro.

 

[gno750]

I guess Dimitri wont be getting help again

 

[DimitriAB]

I guess You guess wrong baby.

 

[gno750]

You dont need to be corgi registered to change a temp sensor ... £2.50 off eBay & do it yourself ....... baby!!