Glow worm 30ci Pressure increase/decrease

[djruk]

Hi all

I've got the annoying GW 30ci combi boiler and unsuprisingly, it has a new problem!

Just fired up the central heating for the first time since last year and the pressure went up to nearly 3 bar after about 15 minutes. When I let it cool down the pressure dropped to about normal 0.8 bar.

Now, thanks to this wonderful forum I've got an idea that the braided expansion vessel hose is probably full of sludge which has now solidified due to not being used for a good few months. So as this isn't the first time I've DIY fixed this boiler I'm going to have a crack at it again - before calling in the pros.

I have taken the front off the boiler and can see the hose in question. I understand there is modified part available, but as a cheap trial/temp fix I'm going to clean and re-use the existing one.

However, as much as I can read, I'm an IT guy and don't do boiler repairs generally! So my questions are:

- Am I right in thinking that closing heating in, heating out and cold water in will allow me to drain the boiler to work on it?

- The boiler has what appears to be a drain tap behind the filling tap. I assume I use this in conjunction with a bucket once the above in/out taps are closed off?

- Does the expansion tank have to be re-pressurised via the valve on top of it? Or is this only if necessary? I saw the section in the FAQ but don't really know if I will need to do this step regardless? I understand the air will be pressurised above the rubber diaphram in the tank so I don't see how draining and refilling would affect it... unless it's leaked or something?

Many thanks in advance.

 

[djruk]

bump... any replies would be appreciated, thanks.

 

[ianmcd]

you dont have to turn off the cold water inlet the expansion vessel is only connected to the heating water circuit, drain that and make sure you release the air pressure charge from the valve at the top of the EV, if you dont you will know all about it, once discharged disconnect the hose and clear it, re connect and then recharge the EV with a suitable pump with a guage, foot pump is fine , take it to around 0.8 Bar remove pump and then open your filling loop until the boiler pressure guage shows 1.5 Bar and you should be sorted

 

[naanbread]

You shouldnt be inside the boiler if your not a gas safe engineer.

Have you considered that it might not be the braided hose? it could be that the expansion vessel is flat or that it balloon inside has failed.
It could be the hose but there are other posibilities. Before you cause yourself more problems contact a local engineer and arrange for them to repair the appliance.

 

[naanbread]

You shouldnt be inside the boiler if your not a gas safe engineer.

Have you considered that it might not be the braided hose? it could be that the expansion vessel is flat or that it balloon inside has failed.
It could be the hose but there are other posibilities. Before you cause yourself more problems contact a local engineer and arrange for them to repair the appliance.

 

[djruk]

you dont have to turn off the cold water inlet the expansion vessel is only connected to the heating water circuit, drain that and make sure you release the air pressure charge from the valve at the top of the EV, if you dont you will know all about it, once discharged disconnect the hose and clear it, re connect and then recharge the EV with a suitable pump with a guage, foot pump is fine , take it to around 0.8 Bar remove pump and then open your filling loop until the boiler pressure guage shows 1.5 Bar and you should be sorted

Thanks Ian. That's very helpful.

 

[djruk]

You shouldnt be inside the boiler if your not a gas safe engineer.

Have you considered that it might not be the braided hose? it could be that the expansion vessel is flat or that it balloon inside has failed.
It could be the hose but there are other posibilities. Before you cause yourself more problems contact a local engineer and arrange for them to repair the appliance.

I'm not interferring with the gas supply in any way, so why exactly should I not be inside the boiler? Forums like this exist to help people. Sometimes people are in a situation like myself where they can't neccessarily just pick up the phone, summon someone and pay for assistance with something they may be able to fix themselves relatively safely and cheaply - as long as they take a few sensible precautions - and key to this... is taking advice from knowledgeable people and experts on here.

I've read up on this very issue and mostly from topics on this forum. It's seems likely this is the problem and one I am happy to attempt to resolve myself. So unless you can tell me I am about to do something illegal - then kindly keep your opinions to yourself!

 

[naanbread]

You shouldnt be inside the boiler if your not a gas safe engineer.

Have you considered that it might not be the braided hose? it could be that the expansion vessel is flat or that it balloon inside has failed.
It could be the hose but there are other posibilities. Before you cause yourself more problems contact a local engineer and arrange for them to repair the appliance.

I'm not interferring with the gas supply in any way, so why exactly should I not be inside the boiler? Forums like this exist to help people. Sometimes people are in a situation like myself where they can't neccessarily just pick up the phone, summon someone and pay for assistance with something they may be able to fix themselves relatively safely and cheaply - as long as they take a few sensible precautions - and key to this... is taking advice from knowledgeable people and experts on here.

I've read up on this very issue and mostly from topics on this forum. It's seems likely this is the problem and one I am happy to attempt to resolve myself. So unless you can tell me I am about to do something illegal - then kindly keep your opinions to yourself!

I think you should take advice that you are being given. I am not trying to cause a confrontation. Im just advising that you should seek advice from a local engineer that will be able to solve the problem for you almost immediately. if you try and fix the problem yourself you could cause many issues, you might cause a leak damaging the software (PCB's) which would result in a VERY costly repair, this is just one example of what happens when people try and fix things when they dont know what they are doing. This is a professional answer from a professional. I am an expert and know an awful lot about these appliances.