Ariston RFFI ACO Boiler problems

[brianmacnamee]

Hello im a newby that is getting pretty deperate wit an intermittent problem with my DHW and CH operating system.
It is a sealed system with 2 pressure gauges 1 on the fill loop and the other on the boiler and 2 two way valves one for the DHW and the other for the CH.
When operating the DHW andor the CH the pump sometimes roars as if there is air in the system with no particular pattern and it sometimes causes the boiler to cut out before attempting to re-ignite successfully before cutting out again and then reating process for 5 times before cutting out for 15 mins before starting again - sometimes with no probs - other times it repeats the roaring/cutting out.Also the system has to be topped up every month as the loop pressure can drop to below 1 bar so its losing pressure/water somewhere.
I also notice that sometimes the boiler press gauge reads zero although fill gauge reads 1.5 bar.
A couple of Heating engineers have investigated the problem and have changed the following items without success.
1.Pump
2.Auto air vent
3.Expansion Tank
4. both 2 way valves (DHW and CH).
All radiators have been bled numerous times but no air is apparent.
Really could do with some advise as bills mounting up and ther does not appear to be any Heating engineers in Norwich/Norfolk area in FIND a LOCAL PLUMBER section.
Regards B.Mac
i

 

[tamz]

Maybe / hopefully, you should /will find a proper heating engineer who will sort this in 1 visit.
I'm sorry to say the trade is not what it once was.

 

[brianmacnamee]

Thanks Tamz
I realise from threads on various forums that Aristons are not the most popular boilers, but I hope i can find someone to take on the challange!! Is there anybody out there in Norwich(Attleborough) area.

 

[brianmacnamee]

reply given by southcoastboile to my original post on a thread to find a local plumber. Hope Im not doin anything wrong Mr administrator.

Re: Ariston ACO 27 RFFI Boiler problems

Sounds like one of the gauges is faulty. If you are loosing pressure check the 15mm pipe that will apear to do nothing and hang out the wall with an elbow on it pointing twords the wall or be run to ground level the other side of were the boiler is loctaed. If this is dripping then the prv will need to be changed, the engineer should also have checked that the pipe leading to the new vessel was not blocked. If there is no evience of any water escaping from the pipe then there is likely to be a leak on the heating system somewere. If you cant find one after checking all rad valves and joints then it would be a good idea to put some leak sealer in the system. It sounds like you have another intermitant fault on the boiler also. It is impossible to say what without seeing it but it sounds like it may be an aps fault/flue fault. If you cant hear it sparking and the pump and fan run then its probably not reaching the stage past aps proving. Make sure when vessel was changed that the flue was put back together correctly if this problem has only started since vessel was done. This fault will need to be checked by a gsr engineer. Hope you find this usefull as it gives you a couple of things you can rule out yourself.​

 

[brianmacnamee]

Hi southcoastboile,
Thanks for help. The overpressure pipe from the boiler is not dripping and the overflow pipe from the water tank in the loft is not dripping either suggesting that the heating coil in the water heater is intact. After removing the boiler cover and the hot water being heated a sound like thr rice crispies cereal popping could be faintly heard. I think it was from the heat exchanger. Further,the pump always seems to be filled with air as ive started releasing pressure on a regular basis from bleed screw. Hope to have an engineer soon but as you can appreciate the good ones are booked up.

 

[tamz]

Where do you live?

 

[brianmacnamee]

Where do you live?

I live in Attleborough, Nr Norwich Norfolk- a few miles from bonny Scotland.

 

[M.Joshi]

If the expansion vessel has been replaced and correctly pressurised, and the pressure release valve isn't letting by, it seems that you have a significant leak in the system for you to have to top-up the pressure every month.

When you bleed the radiators (try a few), what colour is the water? Fairly clear or murky?

If you have copper pipes to your radiators, do you notice any oxidisation (green colour) on the pipes leading in and out of the radiators?

 

[brianmacnamee]

Thanks for reply M Joshi.
The radiators have been bled and the water is clear.
One of the lockshield valves has a slight weep which has coloured the copper pipe but the amount of leakage would not be enough to depresurize the system so much as i opened a bleed screw and collected the water to see how much would be needed to drop pressure appreciably.
The "roaring noise" from the boiler continuous but seems to happen more often than not when DHW is selected on its own. Is it possible that the hot water tank coil is losing pressure into the tank intermittently depending on water volume and hence head pressure in the tank?
How the air is getting in I still dont know.

 

[Roger Welton]

If you are losing pressure though the coil, the hot water can feel a little 'greasy' with the chemicals and muck from the heating system.