How to recharge pressure tank?

[Andeh]

I'm having a release of water down the discharge pipe/tundish, and as it's fresh water it's not from the heating circuit. The heating circuit suffered identical failure modes and glycol water release down tundish, a few months ago, due to a rusted through pressure tank. Replacing the tank with a recharged one resolved that issue.

 

With it now reoccurring with fresh water it has me thinking my pressure tank has failed.

 

I tried the nipple on the top, and pressing down on it didn't release any air... So I'm assuming it needs to be recharge.

 

 I've tried two bike pumps, but neither seem to work, I don't think they are pushing the pin down on the nipple... But the fact they manage it on a bike has me unsure? 

 

Is there a knack or technique I'm missing here? 

 

 

[Nickfromwales]

16 minutes ago, Andeh said:

I'm having a release of water down the discharge pipe/tundish, and as it's fresh water it's not from the heating circuit. The heating circuit suffered identical failure modes and glycol water release down tundish, a few months ago, due to a rusted through pressure tank. Replacing the tank with a recharged one resolved that issue.

 

With it now reoccurring with fresh water it has me thinking my pressure tank has failed.

 

I tried the nipple on the top, and pressing down on it didn't release any air... So I'm assuming it needs to be recharge.

 

 I've tried two bike pumps, but neither seem to work, I don't think they are pushing the pin down on the nipple... But the fact they manage it on a bike has me unsure? 

 

Is there a knack or technique I'm missing here? 

 

 

Probably failed, so it won’t hold the pressure your putting in. 
 

Are you 100% sure you’re getting air into it? 

 

I assume you know the cold mains needs to be off and at least one hot tap open to do this?

[Andeh]

29 minutes ago, Nickfromwales said:

Are you 100% sure you’re getting air into it? 

 

I assume you know the cold mains needs to be off and at least one hot tap open to do this?

 

 

Erm...... 🙃

 

Let me come back to you tomorrow once I've got home and tried it again. Thanks! 

[JohnMo]

2 hours ago, Andeh said:

glycol water

Watch this, lots of reasons to dump the glycol - plus are you managing it's condition and any acidity build up.

https://youtu.be/gHHrQzoX7C0?si=GtEdv9g732mCe_xK

[Andeh]

Well, i turned off the water... And opened a hot tap.

 

I then proceeded to try and pump up the tank... Much to my horror the more I pumped, the lower the pressure dropped. Was starting to really worry. 

 

Then I realised the hot tap was still running, and I was effectively pumping the water out.... 😁

 

Tap closed, and back up to 3 bar... Fingers crossed it stops the water release now.

 

Thanks for the guidance! 

 

 

 

Edited yesterday at 18:48 by Andeh

[Nickfromwales]

18 hours ago, Andeh said:

Well, i turned off the water... And opened a hot tap.

 

I then proceeded to try and pump up the tank... Much to my horror the more I pumped, the lower the pressure dropped. Was starting to really worry. 

 

Then I realised the hot tap was still running, and I was effectively pumping the water out.... 😁

 

Tap closed, and back up to 3 bar... Fingers crossed it stops the water release now.

 

Thanks for the guidance! 

 

 

 

Nope! This is wrong.

 

The taps needed to be left open for the entire duration, so the bladder in the vessel was at its relaxed state. The pre-charge pressure expands the bladder like a balloon, so if you look into the open end of a brand new unit, you'll be able to poke your finger in and feel the bladder pressing up against where the water enters.

 

What you do is open the hot taps and leave then open to fully deplete any pressure in the hot cylinder, then keep pumping until one of two things happens; a) you get the pressure to begin to rise, and you keep going to the required pressure (3 bar for eg), or b) you just keep pumping and the pressure doesn't ever get there.

 

a) means you've been successful, so get yourself off to the pub.

b) means the pubs out, as you need the money for a new vessel.

 

You do NOT take the reading off the vessel when the cold mains is on.

[Andeh]

Hmm, so the tap was left open for 60 seconds or so with cold shut off. I was pumping and pressure falling per previous message.

 

However, when I shut the tap I was able to pump it up to 3 bar very slowly, but it seemed to be steady and touch wood was left at bang on 3 bar. 

 

Opening the hot taps and cold water back on, all seems to flow normally. 

 

Do you think I need to do anything now? Or redo the whole excersise with hot tap open fully for the entire duration? 

 

Edited 2 hours ago by Andeh

[Nickfromwales]

11 minutes ago, Andeh said:

However, when I shut the tap I was able to pump it up to 3 bar very slowly, but it seemed to be steady and touch wood was left at bang on 3 bar. 

You just pressurised the house pipework most likely. 
 

You need to follow the last instructions and do this again to find out if the vessel is RIP. 

[Andeh]

Thanks, I see the point now! I'll give it a go Friday when I'm next free