# Plumber/ Heating engineer help - Combi Boiler top up question - low system pressure



## User62651 (Mar 8, 2019)

Need to top up the system water pressure in my Ideal C32 combi LPG boiler. It's down around 0.2 bar, needs to be between 1 and 2 bar. The expansion tank (out of picture) is pressurised to 1 bar which is about right.

The underside is per the photo.

Which of the two valves are the ones you need to open/turn on to let water in and increase presure? Is it the 2 square brass ones?

What are the red tap valve and yellow tap for?



Looked at numerous vidoes but none look like this, they all have obvious blue taps etc for topping up.

Please dont post with 'get a plumber' - I know that already, just a system top up shouldn't be a major operation. It's good to learn.

I dont know the history of this boiler, inherited it when we moved in a few years ago and the guy before us was a builder so may have done this DIY.

Thanks


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## Stuart_C (Mar 8, 2019)

Feck me that pic makes my pipework look good ðŸ˜‚ðŸ˜‚

Wheres the filling loop? it should be a flexible silver pipe.


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## Stuart_C (Mar 8, 2019)

Which of the two valves are the ones you need to open/turn on to let water in and increase presure? Is it the 2 square brass ones?  *None*

What are the red tap valve and yellow tap for? *The red tap is a gate valve being used as a isolation valve on the cold supply and the yellow is the gas isolation tap.*


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## SocketRocket (Mar 8, 2019)

Its normally by the pressure gauge and a plastic twist grip.


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## User62651 (Mar 8, 2019)

Stuart_C said:



			Feck me that pic makes my pipework look good ðŸ˜‚ðŸ˜‚

Wheres the filling loop? it should be a flexible silver pipe.
		
Click to expand...

I don't think there is one, is there? - the only flexible pipe per the picture is from that red valve going back towards the expansion tank linked to the foreground white pipe, part of the cold water system?


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## Stuart_C (Mar 8, 2019)

Turn the valve below the brass tee with a flat screwdriver.


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## User62651 (Mar 8, 2019)

SocketRocket said:



			Its normally by the pressure gauge and a plastic twist grip.






Click to expand...

Seems to be missing any other twist grips other than the yellow one, a cowboy job probably. I can usually work these things out with a little youtube help but struggling with this.


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## Dibby (Mar 8, 2019)

The cold supply tees off and then goes up the right, what happens there? 
There is another pipe coming back down into the white pushfit elbow, is this connected to the pipe going up? 

You need to show more of the system to have a clue.


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## Stuart_C (Mar 8, 2019)

http://imgur.com/a/yThCHeX


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## User62651 (Mar 8, 2019)

Stuart_C said:



			Turn the valve below the brass tee with a flat screwdriver.
		
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Quarter turn or half turn or keep turning anticlockwise? Will I hear water gush in?  thanks


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## User62651 (Mar 8, 2019)

maxfli65 said:



			Quarter turn or half turn or keep turning anticlockwise? Will I hear water gush in?  thanks
		
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And red tap should be open I asssume?


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## Stuart_C (Mar 8, 2019)

maxfli65 said:



			Quarter turn or half turn or keep turning anticlockwise? Will I hear water gush in?  thanks
		
Click to expand...


half turn so its parallel. Make sure the red valve is open too. once thd pressure is right make sure both valves are shut


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## jim8flog (Mar 8, 2019)

The red wheel on the gate valve also needs to be opened.


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## SocketRocket (Mar 8, 2019)

maxfli65 said:



			Seems to be missing any other twist grips other than the yellow one, a cowboy job probably. I can usually work these things out with a little youtube help but struggling with this.
		
Click to expand...

Its just that my daughter in London calls me at times and says her Ideal boiler has stopped working and shows an L2 error, her water pressure taps are like the ones in the video though.


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## User62651 (Mar 8, 2019)

Stuart_C said:



			half turn so its parallel. Make sure the red valve is open too. once the pressure is right make sure both valves are shut
		
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Doesn't seem to do anything. Turned boiler off and tried the above - Pressure got up to about 0.6 but has fallen back low between 0.3 and 0.4 bar now dropped to 0.2 bar.

The cold water should get into the system from a pipe coming in from above and joins the system 3" or so above the red wheel value. There is a tap on that pipe above the boiler which is open so water running and links to that black pipe coming out of the ceiling. I know that is pressurised cold as that feeds my washing machine off one of those grey utility hose pipes and works fine. Cant understand why when I open the t-piece valve and red wheel it doesn't let mains water into the system??

Does this suggest a leak in the system? Never seen any leaky radiators or wet floors though!
Faulty boiler?
Faulty pressure gauge? Unlikely as we've noticed poor heat output from radiators with low pressure shown on gauge.


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## SocketRocket (Mar 8, 2019)

The screwdriver slot valve (ringed in pink) needs to be turned so the slot is pointing up and down.


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## User62651 (Mar 8, 2019)

SocketRocket said:



			The screwdriver slot valve (ringed in pink) needs to be turned so the slot is pointing up and down.
		
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It was, that photo was taken beforehand. thanks


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## Stuart_C (Mar 8, 2019)

maxfli65 said:



			Doesn't seem to do anything. Turned boiler off and tried the above - Pressure got up to about 0.6 but has fallen back low between 0.3 and 0.4 bar now dropped to 0.2 bar.

The cold water should get into the system from a pipe coming in from above and joins the system 3" or so above the red wheel value. There is a tap on that pipe above the boiler which is open so water running and links to that black pipe coming out of the ceiling. I know that is pressurised cold as that feeds my washing machine off one of those grey utility hose pipes and works fine. Cant understand why when I open the t-piece valve and red wheel it doesn't let mains water into the system??

Does this suggest a leak in the system? Never seen any leaky radiators or wet floors though!
Faulty boiler?
Faulty pressure gauge? Unlikely as we've noticed poor heat output from radiators with low pressure shown on gauge.

View attachment 26744

Click to expand...

Wow.

I'd disconnect the filling loop (silver braided pipe) at the opposite end to the isolation valve, get a bucket  then open the valve with your flat head screwdriver and make sure your getting  water through the valve. 

if that doesnt work then call a profesional out.


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## Bunkermagnet (Mar 8, 2019)

Never seen that many plastic fittings so close to a bolier before...


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## Stuart_C (Mar 8, 2019)

Bunkermagnet said:



			Never seen that many plastic fittings so close to a bolier before...

Click to expand...

Thats got DIY written all over it, shocking installation.


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## User62651 (Mar 9, 2019)

Stuart_C said:



			Wow.

I'd disconnect the filling loop (silver braided pipe) at the opposite end to the isolation valve, get a bucket  then open the valve with your flat head screwdriver and make sure your getting  water through the valve.

if that doesnt work then call a profesional out.
		
Click to expand...

Took filling loop off as you said and no clean mains water at all, so took the braided pipe off at the other end too (thinking in case that pipe was blocked) but pipe is clear. Nothing comes out of that red tap valve when opened. Took the handle off to check the mechanism was turning correctly and it is.

At the other end the t-piece valve works ok - lets pressurised dirty system water out.

Seems that red wheel valve is not letting mains water past, can't see any other valves that could be opened up the line unless that old tap valve near the ceiling is defective. 

Air lock?

Something is amiss, time to get a heating engineer I think.

Out of interest what does that little hex nut (circled red) do - is it just a hole to let air locks out or to drain water out?


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## Stuart_C (Mar 9, 2019)

maxfli65 said:



			Took filling loop off as you said and no clean mains water at all, so took the braided pipe off at the other end too (thinking in case that pipe was blocked) but pipe is clear. Nothing comes out of that red tap valve when opened. Took the handle off to check the mechanism was turning correctly and it is.

At the other end the t-piece valve works ok - lets pressurised dirty system water out.

Seems that red wheel valve is not letting mains water past, can't see any other valves that could be opened up the line unless that old tap valve near the ceiling is defective.

Air lock?

Something is amiss, time to get a heating engineer I think.

Out of interest what does that little hex nut (circled red) do - is it just a hole to let air locks out or to drain water out?

View attachment 26746

Click to expand...

That is a Non Return Valve. Lets water through but nothing back mainly to stop contamination.

Have you opened the other isolation valve (the 1 i circled)with the loop connected?


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## Stuart_C (Mar 9, 2019)

http://imgur.com/a/p5PKkFK


See this pic and disconnect the circled part and open the valve as pictured.

You should get water flying out of the loop


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## User62651 (Mar 9, 2019)

Stuart_C said:



			That is a Non Return Valve. Lets water through but nothing back mainly to stop contamination.

Have you opened the other isolation valve (the 1 i circled)with the loop connected?
		
Click to expand...

Yes, the one on the t-piece you circled pink works fine, colour of water not pretty.


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## Stuart_C (Mar 9, 2019)

maxfli65 said:



			Yes, the one on the t-piece you circled pink works fine, colour of water not pretty.
		
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Ok, either the NRV is faulty, gate valve is jammed or both. either go to screwfix and buy a new filling loop and remove both the NRV and gate valve or ring a pro


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## User62651 (Mar 9, 2019)

Stuart_C said:



			Ok, either the NRV is faulty, gate valve is jammed or both. either go to screwfix and buy a new filling loop and remove both the NRV and gate valve or ring a pro
		
Click to expand...

thanks for your help.


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## Stuart_C (Mar 9, 2019)

maxfli65 said:



			thanks for your help.
		
Click to expand...

Its ok, i'll send you the invoice via PM ðŸ˜


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## jim8flog (Mar 10, 2019)

Stuart_C said:



			Thats got DIY written all over it, shocking installation.
		
Click to expand...

Does the name on the boiler give hint


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## Stuart_C (Mar 10, 2019)

jim8flog said:



			Does the name on the boiler give hint

Click to expand...

If you looked closely you see it was only servicex by that company, not installed. ðŸ‘


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