question foir Gasman or any gasmen out there

[gucciman]

Gasman, i need your input on a problem with an Ariston Eurocombi Styx.

Basically, when a hot tap is opened there is no ignition at the burner. However if I put the central heating on the burner ignites immediately, if I then open a hot tap and turn the heating off the water gets hot and the burner stays ignited until the hot tap is closed.

I fitted a new Diverter valve to this until approx 12 months ago and it seems to be working fine, making and unmaking the micro switches with ease. The instruction manual points towards a fault with possibly the main circuit flow switch, I have examined the operation of this and when the hot tap is opened the plunger moves up and touches the micro switch but not enough to depress it fully, however, when I turn the heating on the plunger flies up making the micro switch easily and igniting the burner.

do you have any idea what the problem could be? I was thinking of changing the main circuit flow switch or diaphragm but thinking about it if it works ok on the heating then it cannot be faulty? I'm now thinking that it must be something to do with a decreased flow or pressure of water thru the flow switch when the tap is opened whereas when the heating's turned on the flow of water must be greater thus triggering the plunger to make the micro switch.

Your advice would be greatly appreciated.

Rob

[Steviegb]

Sounds like chlorifier is blocked / restricted. Ihave had it b4 where the impulse pipes to main circuit flow switch block up (where it comes off 22mm pipe ). Have had problems with pump as well. Anoyher tip with these boilers is the fan venturi starts rusting and u get intermitent h/w, but only if the f/switch works 1st.

[gucciman]

hi steve

thanks for your input mate. i got in touch with aristons technical earlier and their engineer was adamant that it can't be anything other than sludge in the system and advised me to take out and clean the main and secondary heat exchangers. Can't say i particulary relish the thought of that as the styx is a bag of crap and really difficult to access anything, they also seem prone to the joints rusting in, and whenever you force a joint open it invaribaly opens up another joint further down the line leading to a leak.
my father has had a similiar problem before and he also says it could be a pump problem. apprently the styx works like no other boiler on the market and the pump pressure needs to be greater on the water side than on the heating side, so even though the pump seems to be working fine on the heating it could not be running efficiently enough to fire the hot water.