Glow worm 30CI: Sludge in Flexi-hose to Expansion vessel.

RedBeardPete · 11 Mar 2008

We've inherited a Glow-worm 30CI boiler and previously had a pressure drop problem when the boiler was off. The Pheonix gas guy found black sludge in the Flexible hose at the base of the Expansion chamber. Problem fixed.
Now 8 months later the problem is back. Pheonix charge £80 for an engineer to set foot in your house and I am reasonably technically competent but not sure how to takle it.
A. How do I drain the system in order to detach and clean this hose? and B. how do I get at the hose as it is behind the water pump? Can I remove the side panels of the boiler without having to dismantle the pump and the rest of the front assembly?
Any advice much appreciated!

ChrisR · 11 Mar 2008

It's probably a different problem

Sounds like I'm whining like Agile here, but this is typical of where a diy guy can go the wrong way.
You think you have the diagnoosis, but you probably don't know how to be sure. So though generally competent, you could easily spend hours getting to the WRONG part, which a boiler guy would be at in 10 minutes IF it was the right one.

if you don't know how to get tthe water out, perhaps you'd be out of your depth.

We can't really give instructions more than are in the manual - too many what-if's, which experience teaches us how to deal with.

The manual should be on the GW site.

RedBeardPete · 11 Mar 2008

I do have the manual but would probably have to agree with you. Just not mad about paying £80 again

Thanks anyway

ChrisR · 11 Mar 2008

Check the faq first - boiler pressure problems -, or tell us the symptoms!!

RedBeardPete · 11 Mar 2008

The thing is when we first started having problems, the pressure would drop down to 0.6 when the boiler was off preventing it from coming on using the timer. I had to manually increase the pressure to get it to start each time. I had an "engineer" spend two days trying to find the problem checking every pipe for leaks. He also ran some white fluid through the system that was suppose to fix leaks. Didn't solve the problem. Finally i contacted my gas supplier and they sent an engineer who fixed the problem in 1 hour by removing the flexible hose coming from the expansion vessel and flushing the black sludge out of it.

That was great for eight months but now the problem is back. When the boiler is off the pressure is dropping off to 0.6 and has to be manually increased for the boiler to start. When it is running there is no problem. radiators have all been bled and there are no leaks

Agile · 11 Mar 2008

You have not told us what we need to know!

If you pressurise cold to 1.5 Bar then what does the pressure do when you turn on the heating???

At what pressure does water come out of the PRV vent pipe?

Tony

RedBeardPete · 13 Mar 2008

Sorry. When the boiler is on the pressure rises to somewhere between 1.8 and 2.3. ( Don't how to read the pressure when it's on as it changes to degrees C when running so have to turn it off to read.)

It doesn't ever go high enough to flush from the PRV. It only ever did that once when we first had the problem last year

RedBeardPete · 2 Feb 2009

Next chapter in the saga. Got a "corgi registered" outfit to come and do a power flush. they were done in 2 hours and did it on only one radiator. thought that was abit quick. A month or so later and the pressure is up at 3.2bar. Bled some dirty water out of the pressure release until it came down to 1.5 but as soon as I was done it shot back up to over 3bar. help!!! any advice much appreciated.

gavinda · 2 Feb 2009

RedBeardPete said:
Next chapter in the saga. Got a "corgi registered" outfit to come and do a power flush. they were done in 2 hours and did it on only one radiator. thought that was abit quick. A month or so later and the pressure is up at 3.2bar. Bled some dirty water out of the pressure release until it came down to 1.5 but as soon as I was done it shot back up to over 3bar. help!!! any advice much appreciated.

hope they cleared up the horse poo. sounds like you were on the right track with the expansion vessel. why did you have the powerflush done?
sounds like you need a better eng in the house.

Aquaheat · 3 Feb 2009

Next chapter in the saga. Got a "corgi registered" outfit to come and do a power flush. they were done in 2 hours and did it on only one radiator. thought that was abit quick. A month or so later and the pressure is up at 3.2bar. Bled some dirty water out of the pressure release until it came down to 1.5 but as soon as I was done it shot back up to over 3bar. help!!! any advice much appreciated.

When you say as soon as you were done what do you mean by that? The instant you stopped bleeding and got to 1.5 it shot straight back up or when the heating was running it shot up?

Oh and the powerflush doesn't sound as if it were anywhere near close to have been done properly!

RedBeardPete · 3 Feb 2009

Drained a litre or two until it came down to 1.5bar. Cleaned up and came back about 5-10 mins later and it was flashing 3.0 again. From what I've read of powerflushes I agree with you. Had to leave the guy with the mother in Law and go back to work. She thought he was "lovely" and after 2 hours she paid him £249 and didn't get a reciept. Rage.

Aquaheat · 3 Feb 2009

well depending on whether the heating was on or not? (i did ask)

If the heating was still off then have you checked that the filling loop is closed correctly? This could cause a pressure increase while the system stands idle. If this is fine then it could be a faulty DHW heat exchanger and this can be tested by turning off the incoming mains to the boiler.

If the heating was on then its best to check the pressure in the expansion vessel to see if you have a perferated diaphram. This can be tested from the shraeder valve on the vessel (looks the same as a car tyre)

Agile · 3 Feb 2009

RedBeardPete said:
Had to leave the guy with the mother in Law and go back to work. She thought he was "lovely" and after 2 hours she paid him £249 and didn't get a reciept. Rage.

I wish that I had some customers who thought that I was "lovely" !

They always get a receipt though.

Tony

Softus · 3 Feb 2009

Agile said:
...receipt...

Seriously - you're correcting other people's spelling now?

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Glow worm 30CI: Sludge in Flexi-hose to Expansion vessel.

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