Celtic FF. No Hot Water. Any ideas?

[richardeallen]

Hi
I've had a look through the site and it seems like there are quite a few people who know what they are doing so i thought i post my question.

I've got a Celtis FF boiler (pretty old) that works fine in central heating mode but does not give me any hot water.

If the central heating is on and i then turn the hot tap on the main flame goes out leaving just the pilot. Water flows hot for a bit (enough to fill a washing up bowl) but then goes cold (I assume its just residual heat in the boiler). It looks like an someone has tried turning the water temp selector on the front all the way up and damaged the control so now it doesnt turn. Not sure if its stuck on cold or not but i assume because the flame goes out that its not that. It hasn't worked since i moved in (2yrs ago!!). When i did move in the water was turned off so might that have something to do with it???

Any ideas of what i might do to try and fix it or where i might find more info.

 

[lagunaglen]

It could be a problem with the microswitch on the right hand side of the boiler.(in a black plastic box) but not sure if this usually leaves you with no heating. We have one of these on the patch and have to adjust this switch every 3-4 months , but never have a problem with owt else. sure someone on here will have more knowledge of these than my limited one.
Have you switched it to summer setting and tried running the water to see if burner fires up.

 

[hav it]

if it fails or sticks it will give you heating only. diverter assembly is required or failing that rip it off the wall.

 

[Agile]

This is one of the very odd situations I encounter where someone has lived without hot water for two years !

As the boiler is changing its parameters when there is a demand for DHW then I would conclude that the diverter valve is probably working correctly.

It seems very likely that it is a DHW control problem perhaps associated with a damaged pot as suggested.

The obvious answer is to change the PCB or the pot.

Are you a squatter in someone else's house?

Tony

 

[Worldbuilder]

Hi there, i suspect that it is indeed a diverter fault. There are 2 microswitches in the black box above the diverter. One for Ch one for Hw. When there is a demand from the tap, the differential pressure on the diaphragm will lift the spindle and break the bottom switch ( CH ), travel up further and then make the top switch ( DHW ). If the diaphragm is stretched or perforated, there may well be enough movement to break the ch switch, but not enough to raise to the ch switch. You can adjust the switch breakers by adjusting the screws in the housing assy, but generally this will only last for a month or so. All you probably need is a new diaphragm. Hope this helps

 

[richardeallen]

Blimey

Didn't expect quite such a flood of response. I appreciate it all.

To answer some of the questions posted:

A) No I'm not a squatter! We've got an electric shower and a dishwasher and beside I like going to other peoples houses and getting joy from washing my hands under hot running water!!!

B) In summer mode the boiler does not respond to the hot tap in any way. Not a peep.

From what I can gather my course of action should be:

1) Try and adjust the location of the two microswitches and see if that does anything

2) Buy a new diaphram and install that

3) Replace the diverter

4) Rip it off the wall and buy a new one (gulp. I'm skint)

P.s does anyone know a good online place where I can get spares for this boiler?

Thanks again for all the help

 

[Agile]

B) In summer mode the boiler does not respond to the hot tap in any way. Not a peep.

Thanks again for all the help

In that case the diverter is indeed failed.

You may be able to repair it by changing just the diaphragm but a complete diverter valve might be easier.

Be aware your boiler is quite old and luckily there are not so many left still in use.

Parts Center may be best for an older boiler as the on line suppliers mainly just supply the more modern parts which are commonly used.

Tony

 

[richardeallen]

Thanks for the input Agile (and all the others for that matter).

I'm going to have to give the diaphram change a go first simply on the grounds of cost.

How difficult is it for a central heating newbie? I'm relatively clued up spanner wise (dont worry I'm not just going to go tearing into my boiler if i/you think its dangerous). But if its a relatively servicable part and its a case of draining the system and shutting of the gas/ electric then i think i could tackle that ok.

Any thoughts on where to look for further advice/instructuions?

Thanks again for the help.

P.S, I've got the Pro's coming round to inspect the system anyway. Would they charge much to simply change a diaphram do you think?

 

[tryitandsee]

The rubber diaphram only costs about £10. Plenty of them about.

A good (senior) plumber would know what to do blind folded, as the diaphram should be replaced every two/three years anyway, (pre-empting your problem, no hot water.) Ask him to do a service at the same time letting him know that it requires a new diaghram, so he can get the part before he arrives.

Worldbuilder described it spot on.

 

[tryitandsee]

Don't know if this link will work!


http://www.hccfspares.co.uk/Part_Type3.aspx?Manufacture_ID=18&Part_Type=DIAPHRAGM

 

[richardeallen]

Thanks again to all for the help.

I've ordered my parts so now I'll just see what happens.

p.s. tryitandsee your link worked a treat. Diaphram cost me £7 but with post and packing it came to £17 !!!

Still if it works its cheaper than the new boiler I thought I'd have to buy.

Cheers

 

[hav it]

dont bother replacing the diaphram replace the unit it will be less hastle. remember its a chaff

 

[richardeallen]

Sorry mate you've lost me on the chaff?????

From what i can tell a unit is £100 ish and diaphram is £17. I really am skint at the moment hence the no hot water for two years!!!

Saving up for a trip around the world and need to rent the house.

don't want to do anything dangerous thats why I'm getting my CH inspected. Just thought I'd try and cut down costs wherever i can.

Is it a terrible idea? I take it chaff doesn't mean something like Could Harm All Fixers Fiercely?

Cheers

 

[tonybhoy]

Chaffetaux, French for piece of merde

They made your boiler.

You must be mad to go round the world and then rent a house out with that boiler on the wall it will cost you a fortune in repairs,unless of course the new tenants are squatters

 

[hav it]

lmao chaff = Could Harm All Fixers Fiercely


Iv lost count of the amount of pots and pans, iv taken out in the kitchen trying to sit the vessel out the way to service or repair.