Ariston Microcondens

[DP]

This post is an "in desperation" as no one has replied to offer useful advice (so far) to posts elsewhere.

Would like to discuss ins and outs of above boiler. Gas valve was changed but lasted three days. Boiler is back at ignition lockout stage.

Hopefully I will see the client tomorrow to not to kill the boiler and and the client for choosing such a cr**py appliance whith technical hot line not worh the long wait.

 

[Slugbabydotcom]

Never seen other posts but can offer you MI's if you need them.

 

[Agile]

You cannot "just change" the gas valve on a premix boiler.

You have to adjust the mixture on the gas valve whilst monitoring the CO² percentage which is usually specified as about 9.0%. Check the MI for the correct valve and if you set it at minimum or maximum power.

Tony Glazier

 

[DP]

Tony the boiler first has to complete ignition mode to allow aforementioned flue gases to be checked. The boiler is NOT doing this. Boiler is locking out for flame failure.

What I need is assistance like I gave you by email when you asked for assistance on another boiler. Mts can only suggest 'change this and change that'.

 

[Agile]

Its a little difficult for me to guess at the problem as it was apparently working for three days.

I am not familiar with that particular model although most boilers follow a similar theme.

Generally there is a gas pressure which can be preset on the gas valve as an initial starting point. Often only about 0.5 mB so it needs a digi manometer!

Next hopefully there may be a viewing window to see if its sparking. If not the the ignition electrode can be withdrawn to confirm its sparking.

Once it can be got to light then the FGA setting for the CO² is the next step. From what you said elsewhere it sounded as if the mixture was weak.

If the boiler is run with a seriously weak mixture it can "backlight" onto the inner gauze within the burner tube. This can cause damage.

Tony

 

[DP]

Tony from your post it would seem you are not familiar with this boiler.

There is no viewing window. Spark is present. Gas pressure cannot be measured on delivery side of the gas valve with a digi manometer, premier guage or a standard one.

What I need is specific help instead of general guidance. All I do is boiler repairs, so I am familar with how a boiler operate sequence runs. In fact I go to great lengths to get to know a strange boiler in order to carry out effective repair without changing parts needlessly.

To date Mts has not been of assistance. Am hopefull tomorrow will be a better day when I call them.

 

[Agile]

When you changed the gas valve and it was working did you measure the CO² percentage and set in accordance with the MI ???

Tony

 

[Slugbabydotcom]

Perhaps this may be of some assistance.
Theres a link there where you can download the pdf info for the gas valve

 

[DP]

Yes Tony, I did. You will note the boiler worked for three days.

Slugbaby, thanks for the link. Link clearly shows what happens in the gas valve. Instead of looking at a lump of metal, the link shows progress of gas with test relevant test points.

 

[ChrisR]

Call to SIT might be interesting -
01925 290660

 

[Softus]

Once it can be got to light then the FGA setting for the CO² is the next step.

There's no such atom as O² - did you mean CO2?

 

[ChrisR]

There's no such atom

Indeed not.

Did you mean molecule?

 

[Softus]

No - I chose the word carefully.

Although free Oxygen tends to bond diatomically, to form O2, the bond in a molecule of CO2 is not a diatomic one, AFAIK.

Agile wrote CO², which is a non-existent compound, since this would combine one atom of Carbon for each atom of squared Oxygen.

 

[gingerbreadperson]

awayyaegoyafud

 

[sime10]

Glad to see you shed a bit of light on that gingerbreadknob