Ariston ACO 32 MFFI Combi - hw only warm unless htg on

[johno_uk]

Went to the above boiler last week, it kept blowing fuses. On looking at it, it was the div valve pin leaking onto the motor. I used the service kit and replaced the guts of the valve and the valve motor. Ran the boiler and tested hw and htg =happy days.

I got a recall today as the customer says the hw only gets Luke warm unless the heating is on??? I went round and the hw comes on when the tap opens as expected and the water heats to what I thought was not bad at all. But the customer was addement it was like "fire water" before it started tripping out last week. I tried to explain that the boiler can only heat upto a certain temp rise etc etc. then he put the heating on and To be fair when he ran the heating and then opened the hw tap, it was coming out hotter? When only the hw is on, the flow and return from the main hex into the plate you can hold without burning your hand. When heating is on it's too hot to touch. I would of expected it to be other way round with it firing on max rate on hw demand?

I didn't have long to look at it tonight but the hw thermistor was fine. I'll gas rate it and recheck pressures again tomorrow (we're fine after changing parts last week) failing that I'm putting it down to scaled up plate as its 6yrs old and there's no scale reducer filter fitted.

Been a long day, Any ideas or suggestions welcome. Luckily don't come across many aristons.

cheers

 

[ambrosia]

last time i changed those springs under the actuator it released loads of crap into the plate hex, did you change the bottom spring as well

sorry just re read your post, not sure if what i said is relevant

did you make sure everything was lined up, if you take the flow pipe off the manifold and shine a touch down you can double check its gone together as it should

 

[johno_uk]

Thanks for reply. I think it only goes in one way, it fit in securely and doesnt leak? Will check out the flow pipe on manifold to see if it looks ok. Cheers