Boiler has no markings on, but have manual that says...

Fanned Combi

RSF 84E - RSF 100E
RSF 84ET - RSF 100ET

We have a 5 year old ravenheat combi boiler, always had intermittent problems, but they have always sorted themselves out, but there is a new problem & it isnt going away, help!

central heating works fine, but hot water is a problem.

Turn on hot tap and 80% of time it will fire up.

If i try to adjust the tap, ie use mixer to add cold water, or reduce the pressure the boiler cuts out.

Some times there is a sort of whistling noise coming from the boiler, a bit like a kettle? this can happen with CH, but 99% time happens with water.

Pilot light does not stay on, but lights itself every startup, i found this strange?

The pump is set on II, but there is a plastic box next to it with the same markings (I, II, III), but it is set to I, should these be the same?

When i run a bath there also seems to be some small black specks (1-2mm) appearing, when touched they leave a stain on the bath, it cleans off but i guess they shouldnt be present?

The breather on top of the boiler has alot of build up around it, will this cause problems?

Since i removed the lid & checked tightness of everything i think i may have knocked the "safety releif system", a knob under the pump, it started lowering the pressure, so i tightened it back up, but ever since it has been dropping pressure, oops!

Dont know if these problems all tie in or not, but some answers would be good, i will be getting a pro out, but we got duped last time & would like an idea of what needs fixed before we get someone out.

many thanks!

Mark Donn, May 2008

3 way valve leaking out of 2 small holes in middle of the valve . is the leak on the piaphragm side or the heating system side

ste, July 2008

really think you should get somebody who is qualified

der, May 2008

Totally unresposive today.

Is the diaphram in the 3 way valve?

Whilst having another look today, i had a look at the two wires that go into the three way valve, there is a black box they go into, and can not be opened unless the valve is removed, i gave them a little wiggle(as you do when fault finding) and the boiler fired up for 30secs, then died, then with the hot tap running and no boiler firing, i moved them around & there was another click & it fired up again, it is now possible to fire the hot water for 30 secs by moving these wires, but i need to know what to replace, is there a switch in there?

That would allow the boiler to fire, then just need to figure how to keep it going!

Thanks for help so far.

Mark Donn, May 2008

Sounds like you need a new diaphragm-probably worn. Not an expensive part. Whistleing could be scale, but I'd try diaphragm and see how it runs. Supposed to ignite on each demand. Pressure relief valve can be cleaned, but sometimes don't seat very well after they've been operated and may need replacing. Auto air vent will need changing if leaking, otherwise just monitor it. Pump should be set to III.

Kev, May 2008