Ariston Micro Genus Problem

[Agile]

Power Flush will usually make no difference because those who do it mostly ignore the boiler!

GG has reminded me that the pressure switch is a modification of the flow switch and not as I was describing to clear the waterways.

They can be carefully removed and will often reveal lots of gunge behind which can be cleaned out. They often leak after refitting even of they were not before!

GG has evidently found some way to identify which ones have the LP switch but I always have to look inside!

Tony

 

[DP]

Boiler locks out on startup after a period of inactivity. Blockage would cause a problem regardless of 'sleep' between activty.

I say the sensors are drifting out of operational window. On self check when boiler starts up after say 20 minutes, sensor reading incorrect so boiler goes staright to lockout. When 20 minutes is reduced to 10 or 5, boiler fires up without a hitch.

 

[djangodjango]

Are these sensors easy to check / fix / replace ?

 

[Gasguru]

Dunno what DPs on about

The differential pressure switch needs to be checked out. When the boiler refuses to start, the reed switch contacts need to be checked for continuity when the pump runs. This will verify whether there is a problem with the diff. assembly or a weid pcb fault.

 

[DP]

Gasguru, the poster lives up the road from me and I have not been able to attend due to heavy workload at present. am in communication to do so after the new year

My thoughts are based on boiler, once it starts, will run as expected until the demands on boiler ar in order of 15 minutes or more. Boiler need to be reset several times to eventually starts working and run all day as long as demands are less than 10 minutes or so apart.

Also, boiler goes to immediate lockout if left 'sleeping without demand' for 15 minutes or more. If I remember correctly, the flow switch does get sluggisg but does not cause immediate lockout (infact, does the boiler really lockout if the flow manifold was malfunctioning- I cannot remember)

I follow your posts with interest, so any nuggets of gold will certainly restore boiler operation for this gent.

 

[Gasguru]

AFAIR once the pump runs the pcb will sit there for a short while waiting for the diff switch to activate before throwing on the "pressure light" (the LED next to the triangle pump symbol).

Just check the reed switch on the side closes when the pump runs. The reed switch is mounted on a small pcb clipped inside a plastic housing which slides off the side of the diff. assembly. I've had the reeds soldered in the wrong orientation giving intermittent operation.

Check the magnet is free to slide within the housing.

Take a diff. diaphragm with you. With the diff. assembly off the diverter manifold the centre drilling intercepts a drilling from the left hand side (where the flow pipe from the primary heat exchanger connects) providing positive pressure. The negative (front) side of the diapragm is fed from a drilling on the left leading back to the bypass assembly at the back. Bowden cable is useful to feed through and clear blockages.

I think the OP said there's a new pump, otherwise check the torque/impeller.

I'm assuming the basics have been done...AAV ok, expasnion vessel pre-charge ok, the pump plug is properly connected.

If everything's ok then it got to be blockages in the pipework/hex/connections.

I suppose it could be a bizarre pcb fault. Check the connector joints.

Good stockist of Ariston if you're stuck over Christmas... http://www.deansgas.co.uk/index.asp