More WB combi boiler woes

[Andrew Collins]

Last episode I had a Worcester Bosch 240 with a leaking PRV, even at 1 bar.

Hopefully I now have a Worceter Bosch 240 with a working PRV (replaced). Everything seemed to go OK with the replacement, but now the boiler won't start :- the thermal cut-out keeps triggering.

I suspect this is because the boiler itself is still half full of air :- obviously I had to drain it to replace the PRV.

I've checked the CH circuit isolators and both are open, so it's not that. The pump does make a "I'm full of air sound", then the burner kicks in and all sounds well for a few seconds. Then we get a bit of air and the pressure gauge goes a bit woo and the thermal cut-out pops out.

Any tricks to getting the water out without just resetting the boiler and retrying every half hour?

Thanks,

Andrew.

[Andrew Gabriel]

It should say in the instructions. For my Keston, you fire it up with the gas supply turned off, which will eventually trip the lockout when it gives up trying to light, but leaves the pump running. Also there's an automatic air vent on the heat exchanger outlet. Firing up in the way you have without purging air from the system is specifically listed as invalidating the warantee on the heat exchanger on most boilers.

[Andrew Collins]

I've evidently not got the right instructions...

Yup, the pump stays running. Unfortunately this alone doesn't seem to sort the trapped air problem out.

Aah... now that would be useful. Knowing my luck there will be one but in the same condition as the PRV :- totally u/s.

It's a Worcester Bosch 240. They stopped making them last millenium, so I don't think the warranty is a problem. Nevertheless, clearly not a good idea. Not that I knew that ten minutes ago.

I'll have a second scan of the piece of A3 I have that claims to be the boiler instructions. Perhaps I missed something.

Cheers!

Andrew

[Ed Sirett]

I was doing this with a W-B 24SBi this morning.

1) Just give a quick turn on-off with the boiler thermostat, the pump over-run timer will give you a minute or so of pump running. Or turn the gas inlet off, but then it'll lockout eventually. 2) Use the auto-air vent (which was broken in my case). 3) With a towel in position to stop drips into the electrics, slacken the bleed screw on the back of the pump. It will "squzzle" when there is a lot air in the pump, so you'll get the water flowing and the air into the rads.

IMHO they messed up with the pump position. Pumps should pump upwards that way the air, pump and water don't work against each other but with each other.

Note that the back of the pump will appear to drip for a few minutes after closing the bleed cap.

[Andrew Collins]

Yes, following up my own message, I know! :)

Andrew Gabriel, any time you like I'm round yours with a pair of backless leather chaps and a tub of vaseline.

In the spirit of adventure, or to be more honest the spirit of "Oh my God I hope my bad DIY is covered by my house insurance", which alarming it does appear to be, I tried turning off the gas and then turning on the boiler.

It gurgled.

It popped.

But by and large it got quieter. I gave it about 15 minutes and it seemed to then sound pretty much like normal.

So I turned it off, turned the gas back on and fired it up and it's still running after half an hour or so and we have hot radiators again!

Many thanks to the people that have helped me and my numptyism with this boiler, as I've said before, your average car engine, not a problem. Boilers, I ain't got a friggin' clue!

Andrew

[John Rumm]

Now you just need to find the rad that has all the air in it that was in the boiler and let it out (you may need to top up the pressure after bleeding it).

Don't forget to stick some inhibitor in there if you have not already done so.

[Anonymous]

: Now you just need to find the rad that has all the air in it that was in : the boiler and let it out (you may need to top up the pressure after : bleeding it).

My missus was complaining this morning that the radiator in the bathroom (which is almost directly above the boiler) was gurgling, so that's my starter for 10.

: Don't forget to stick some inhibitor in there if you have not already : done so.

There's allegedly some in there already, but I fear it will have been seriously diluted by the continual topping up and now this latest episode.

Two questions.

Firstly, given that I have no idea what product is in there (inherited with the house), would there be such a thing as the wrong product to put in (like topping up a car engine with the wrong type of anti-freeze)?

Secondly, does anyone have any recommendations?

Thanks,

Andrew

[John Stumbles]

Ooh-errr, is there a wromg sort of antifreeze? I just put in whatever was cheap at the factors. I thought the only wrong sort was 'no' antifreeze :-)

Funny how these questions always seem to come up in different threads at the same time.

http://82.24.138.95/~john/Inhibitor

[Andrew Collins]

: On Thu, 05 Jan 2006 12:52:05 +0000, com.hotmail@bflfcbb wrote: : : > On Thu, 05 Jan 2006 10:28:30 +0000, John Rumm : > wrote: : : > : Don't forget to stick some inhibitor in there if you have not already : > : done so. : : > Two questions. : > : > Firstly, given that I have no idea what product is in there (inherited : > with the house), would there be such a thing as the wrong product to put : > in (like topping up a car engine with the wrong type of anti-freeze)? : : Ooh-errr, is there a wromg sort of antifreeze?

Was. I remember my father talking about it when I was young and first developed a real interest in cars. I think he was talking historically then, and that would have been 25 years ago at a guess.

Modern anti-freeze is ethelyne glycol based and is blueish. Apparently though there used to be another (cheaper) anti-freeze. I can't remember what that was based on and it's only the finest fibre of memory that tells me it was red. My father recalled all sorts of dire warnings about mixing the two.

Of course, he could have been talking twaddle, but he's usually pretty reliable about this sort of thing. : > Secondly, does anyone have any recommendations? : : http://82.24.138.95/~john/InhibitorOoh blimey, science? Surely there's no room for that in this era of product marketting? :) Thanks, that was most informative!

Andrew

[<me9]

The cheaper one was methanol based (a bit like screenwash is) the problem (apart from mixing them) was that the methanol having a lower boiling point could evaporate out, leaving a lower strength mix.