Please help I have a problem with my Ravenheat fanned combi

[Totallyconfussed]

I have a Ravenheat Fanned Combi RSF 82E -RSF82ET that is covered by British Gas,on wednesday it had its annual service check the guy said the pressure was low so used a footpump on the top of the boiler,he then checked all the radiators no problems so then he left.
Went to have a shower and the boiler started making loud noises as if it was boiling over.Called BG back engineer arrived today turned a tap on and said my heater exchange is scaled.
Please tell me how it can become so scaled in an area that does not have a scaling problem and to do it within an hour of an engineer saying everything was fine.BG then tells me that it is not covered under my contract,cost nearly £300 to replace then £600 to flush the system.Is it my boiler or BG ???

 

[gas4you]

If it is scaled up then a powerflush will not help. If it is sludged up then a powerflush will help.

Don't know how the first engineer could just get a foot pump out, the boiler would have to be drained to pressurise the exp vessel.

The 820 has a twin coil HE.

I would get them back again.

 

[gasmick2]

Hi it seems a bit strange to me if the boiler was working ok before
and like the other post has said the boiler would have to have been drained before attempting to represurize the vessel its only got o.7 bar in it anyway
i am wondering if he has forced a lot of air in and ruptured the diaphram inside that will cause the boiler to make all sorts of bumping noises when in use
It also seems strange that when he said the pressure is low pehaps he ment the water standing pressure which should be 1.0bar at cold
Perhaps he thought thats where the pressure needed to be put up
if he put a foot pump on it and kept pumping it will show on the pressure gauge on the front as it is forcing the water back into the system and so making the pressure behind the diaphram greater
it sounds like the pressure needs releasing back to the correct pressure
most engineers dont bother to check the vessel pessure unless there is a problem reported like a lot of noise or water contantly blowing off out of the pressure relief pipe
mick

 

[Slugbabydotcom]

Noisy operation is not uncommon with this type of boiler. Part of it is due to a design fault that was overcome in later generation boilers. When it gets excessive most of it is attributable to poor flow through the heat exchanger and low system pressure as well as the black crud that you find in systems.

Some earlier Ravenheats have adjustable speed pumps. A possibility is that he has reduced the pump speed as is best for a conventional system but not a combi. If you can adjust it then it should be on speed 3.
When a ravenheat pump is on its way out there is usually a small leak from the bottom of the head where it joins the impeller section. It also becomes noisy

What does the pressure gauge read now? I'm wondering if the schrader valve could be leaking on the pressure vessel since he played with it. Its just as you would find on a car tyre and as someone who has fitted a lot of tyres I was taught to put a tiny bit of spit on the valve after inflating it and watch for it bubbling. Soapy water works just as well.

Don't take this as an accusation but as food for thought
Seeing as BG engineers get some pocket money for selling a new system they have inadvertently given an incentive for some of their engineers to try a dirty trick or two. I wonder if it is on their agenda to try and sell you a new system or if they also get a little extra for drumming up more work. Hopefully they are just trying their best. I'll leave this paragraph open to discussion.

It is not good that they have serviced your boiler and you now have problems that you didn't have before. I would be inclined to threaten them with the sale of goods and services act and get them to justify their position. If it turns out that your pump is coincidentally faulty then I would accept that as I have changed a disproportionate amount of ravenheat pumps lately. 5 since christmas = They must be in season!