Broken Again-Worcester24CDI stopped working after..

[sm1thson]

---broken again see 5th post down!----

i have a Worcester 24CDI, yesterday i flushed the system using a hose on the flow and one on the return (boiler return valve in off position) turning all but one radiator off individual/ly, and addeded some TRV's whilst i was at it (not to every radiator). repressurised and blead all last night. Heating and hot water working great last night and this morning.

then this morning i part drained one radiator, and added chemical treatment (wickes) in view of flushing it again in a couple of weeks and adding inhabitor.

now the boiler has stopped working. turning on the hot tap it all works for a bit then the flame goes out and it goes cold!

tried to reblead the pump but just hot water comes out and it very hot.

pressure is at 1.1 bar and raises to about 1.4 when system is running. (edit-now goes to about 1.9 before boiler shuts of on dhw, i presume to overheating as the pump gets v hot)

what can i test? (i have a multimeter and know how to use it if that helps but i expect its something mechanical given the scenareo)

the system wasnt in that bad state its just i had to put a radiator back on after decorating so figured i needed to top up with inhabito and may aswell flush it first!

one thing i wasnt completely sure on is bleading the pump. i undid the screw on the front and took it off untill just water was comming out and replaced it. -is that right shall i do it again once its cooled down?

edit:
i think the pump works still as when i turn the system on i hear it go with a swoosh noise (i think from the expasion tank)

looking at it again it looks like i didnt run the heating for long enough afterwards, it says to 'turn the boiler on then blead radiators again after an hour' (so technically it doesnt say to turn the heating on!), looking at the timer it will have run for about 15 mins give or take. -had the blocked something? -what would it block? -heat exchanger?

edit:
Ive now put the C heating back on to try and shift it, pump is pumping and flow pipe is hot pressure staying steady (even when burner come on -but it doesnt stay on for long i suspect because the heats staying where it is!) rad pipes havent got warm yet which i would have expected (been on 5 mins).

Edit:
think it may be sorted, the rads stayed cold for ages, but now they have started heating up and the burner is staying on ( iwill leave on for at least an hour!) and the pump has quietend down.
i think it was a case of the radiator i poured the chemicals in was probably the worst as it has been sat in the garage for a few months (i did run a hose thru fisr but that wont of got everything) so the chemicals will have got the rust of the inside quick then the heating ran for a short time and turned off dumping it all in my heat exchange blocking it. persistance seams to have unblocked it so i will see how it goes.

Edit: DHW works fine now also -flame stays on and pressure stays stable. will leave heating on for 1.5 hours and all should be good i hope!

(edit: thought CH had stopped, but someone had turned thermostat down, lol so situation is still as above, wasnt working now is so all should be good if i leave it alone!)

edit: CW and DHW been working for over 1.5 hours now so I am assuming it is sorted!

 

[Agile]

"""and added chemical treatment (wickes) in view of flushing it again in a couple of weeks and adding inhabitor. """

Just why dont people realise that you MUST use a proper branded inhabitor (?) like Fernox or Sentinel ( or to keep Keith happy Camco ).

Tony

 

[sm1thson]

fair enough agile. i bought them when i first bought the house in summer and started going on DIYnot i have seen since thought 'should have bought fernox' etc but figured I'll stick with what i had. given that i intend on putting the inhabitor in (after flushing) and leaving it, i think i will take back the inhabitor and get some proper stuff.

where's the best (cheapest) place to get some fernox, Sentinel or Camco?

p.s. its still working.

 

[ChrisR]

Just why dont people realise that you MUST use a proper branded inhabitor ....
to keep Keith happy Camco

Moobay its becorss thay get tolled the wromg names.

It's KAMCO !

Any plumber's merchant will stock a selection.

By the way Fernox have made several heating elixirs for Wickes, but I don't know if they still do.

 

[sm1thson]

Now the DHW water light has started flashing. it occurs about 1 minute after demand. according to the manual Ive downloaded this means its either an air flow fault (RSF) or fuel / combustion spillage (OF), i dont know if i have RSF or OF type so here are some pictures of my flue:
inside Picture
outside picture
I cant see how what i have done over the last couple of days has effected either of them!?!
the only thing i can think of is the air switch thingy which for some reason lays loose in my boiler, i may have moved that slightly and upset it? -how do i test if this is a problem? ( picture of airswitch thing) any ideas?

 

[sm1thson]

Its still not happy guys! its only a problem on hot water (ie CH works fine) i presume this is because of the extra power used to heat HW.

listening to it tonight i did here the pressure switch click off first then it go into the fault condition. so iguess it is either the switch loosing its spring or the fan is playing up/ a blockage. i do have access to a manometer if some one can tell me what pressure the switch should activate!?!

only thing i can think of is the fan etc got a bit 2 hot when it was playing up (first post) and this has caused it to loose its effectiveness?? -any other ideas???

 

[pannierstan]

I think you might find its the Autoair vent actually. They are crap on the Worchesters and usually dont Auto vent hence the boiler is constantly airlocked especially when on dhw.

Stan

 

[sime10]

by the way its RS FF

 

[sm1thson]

by the way its RS FF

thanks

I think you might find its the Autoair vent actually. They are rubbish on the Worchesters and usually dont Auto vent hence the boiler is constantly airlocked especially when on dhw.

Stan

right i looked at my auto air vent last night and its green and furry so undoubtably needs replacing. i will do this (probably saturday so may try manually purging and sealing the other one tonight). i suspect the AAV may well have been the problem in the first post but i cant see how it will have caused the boiler to report a flue problem?

last night i layed the air switch thing on its back, and in that postion it the DHW works fine (nice hot bath this morning). presumably because it is dying and that helps it, or there is a problem and lying this switch on its back gives me a few extra mbar before it actuates -just enough!

 

[pannierstan]

Well the air pressure switches are prone to problems aswell so if you have one of the old brown ones get it changed. If not change it anyway if it only works lying on its back.
Might be fan venturi I suppose or the pipes from there to the switch which were also modified as they were brittle and started cracking.
Tell you what get an engineer in who knows what he is doing. Far easier although a little more expensive.

Stan