Megaflow passing a lot of water when recharging air space..

[ryoc]

Normally when I recharge the air space in our Megaflow (approx. 8 years old, in the loft), holding open the valve, a lot of bubbling from within and a little water passes the open visible area. Recently, when holding open the valve, a solid stream of water pours out for over a minute, then a little hissing. Is this normal? I have put posts on here previously as I get a lot of noise from the boiler/Megaflow area during the night. Much louder than normal boiler operating sound. Not sure what's causing it. Maybe a Megaflow related problem? Thanks -

 

[Heating one2one LIVE]

It could be the baffle inside isn't recharging.Does the temp/pressure relief valve intermittently drip?If so then its either new cylinder time or cut an external one in on the hot supply.
This is all if you are recharging correctly of course.

 

[oilhead]

Do you have a backfeed from for instance, a shower mixer?

 

[screech]

It could be the baffle inside isn't recharging.Does the temp/pressure relief valve intermittently drip?If so then its either new cylinder time or cut an external one in on the hot supply.
This is all if you are recharging correctly of course.

last time I spoke to heatrae sadia about an external expansion vessel on a megaflo i was told it's not allowed

 

[ryoc]

Thanks for the replies. There is no dripping from the valve. I am getting loud noises from the Megaflow area (in the loft) during the night, when the boiler is not in use (except for heating the towel rail, seems to work independently from the time switch?). Recharged again to today, in accordance with instructions on the tank. Steady flow of water from the valve for approx. one minute, with no hissing or gurgling..

 

[ryoc]

Do you have a backfeed from for instance, a shower mixer?

Sorry, not really sure what a 'back feed' is, but there is a power shower in the bathroom which I guess is fed from the megaflow. Cheers - Paul

 

[oilhead]

Back feed is where a thermostatic mixer has been fitted witout non return valves. This allows mains water to feed back through the hot suppply when the hot pressure is relieved by turning off the mains feed into the megaflow

 

[ryoc]

I have been advised by Heatrae Sadia that the problem could be caused by a blocked strainer in the Cold Water Combination Valve, and this could need cleaning. There is an allen key attached to the valve, is it a diy job to clean it? Switch off mains supply and take the end off the valve?

Also mentioned was balancing the hot & cold..

 

[oilhead]

This is the sort of situation where a G3 ticket is needed. I would call in such a qualified person.

 

[ryoc]

OK, thanks for that. I will call in some professional help.. I need to get this sorted so we can all get some sleep... Cheers -