Help! leaking megaflow

joepubli

A couple of month ago I moved into a house with Megaflow. Heating stopped working. Looked at the pressure gauge by the red bottle was at 0- so repressurised to 1 and everything was fine for the next 6 weeks.

Megaflow cylinder is in a cupboard above kitchen. Yesterday I see a pool of water leaking through the ceiling where the megaflow is into the kitchen. I switch off the boiler and go and look. in the cupboard. Very hot water and pressure being released. hissing.

I follow the instructions on the cylinder to reset the airgap - switch of cold inflow. open hot water tap and open the pressure valve - lots of gurgling for 10 minutes and eventually water stops from the hot water tap. I reopen the cold water inlet and shut the hot tap when water comes from it. I leave the heating boiler switched off. Leak stopped. So I think I have reset the airgap.

In the morning I have a shower. There must have been some hot water in the tank from before as it had been switched off.

This afternoon I want to put the boilerback on . But I lcheck the pressure gauge by the red bottle -its 0. So I pressure it to 1. A few minutes later go into kitchen to switch the boiler on and water is agini dripping off the ceiling - and the pressure gauze is back to 0.

What's going on please? I will look for a plumber but would like to know what could be the problem. Are their plumbers that specialise in Megaflo?

Canucklehead

Hi,

Yes ,to work on unvented cylinders you need G3 qualification.

However your problem is with the central heating system. The red expansion vessel needs the air charge topping up and then check the pressure relief valve as it may well need changing .

Posting a photo would be useful.

GSR.

joepubli

Thanks Canuklehead. But how can it be the central heating system if it wasn't even switched on when the water leaked out the second time? Not sure how to put pictures up here as it seems needs to be on a website. Will check and post.

joepubli

http://i1090.photobucket.com/albums/i377/joepubli/image1.jpg

Megaflo - I followed the instructions on the label. Temperature/pressure release valve just below the label

http://i1090.photobucket.com/albums/i377/joepubli/image3.jpg

pipework

http://i1090.photobucket.com/albums/i377/joepubli/image2.jpg

This one shows the red tank and the pressure gauge at 0.

joepubli

Canuklehead,

OK, I think you are right and it is the central heating system rather than the Megaflow.

When I top up the pressure, the water is dripping through the left hand thread of red Grundfos heating pump. See picture below - you can see wet wood and I saw it dripping as soon as I open the tap on the silver pipe to increase the pressure

http://i1090.photobucket.com/albums/i377/joepubli/pic4.jpg

Is it just a matter of tightening the thread with a big spanner? This will need a very large spanner. I cant understand why all of a sudden its leaking. Does it indicate too much pressure etc?

Is there a quick way of fixing it?

Canucklehead

Hi,

Could you confirm or deny the following.


On the pressure gauge assembly: is there a 15mm pipe going away from this assembly to outside, or does it disappear out of sight, or isn't there one?
Next.
If there isn't one, and the speedfit cap fitted under the gauge is where it should be, then you have a totally sealed system where there is nowhere for excess pressure to escape.It has found the pump union to be a weak point.

If this is the correct diagnosis then be grateful that the pump union is your only problem.

It will need the pump union taking apart and probably a new washer.
The expansion vessel needs checking (pre charge pressure) and the pressure relief discharge running to outside.

There is also a rusty looking mark on the connection to the EV I would want to know where it's from.

I might be wrong of course.

GSR.

keystone

Canucklehead wrote: »

If this is the correct diagnosis then be grateful that the pump union is your only problem.

OP pay close attention to what CH says. You really should get someone in to look at it even if just for the pump union 'cos like as not you'll neither have the correct tools nor the knowledge to know just how much brute force you can apply without breaking anything.

I might be wrong of course.

Even if he is, which is unlikely, you should get it looked at.

Cheers

joepubli

Canuklehead
Thanks for your help.

As this picture shows
http://i1090.photobucket.com/albums/i377/joepubli/photo5.jpg

there IS a pipe leading away from the red valve. It follows the oveflow out of the building.

The pipe with the waterpump connects to the bottom of Megaflow marked "Primary Flow". Thee other end I guess goes to the boiler?
http://i1090.photobucket.com/albums/i377/joepubli/photo6.jpg

Keystone - Yes, I will need to get someone to look at it rather than dtry and do it myself but I wanted to understand what's wrong. - it seems strage that the joint just leaks now, I suspect there must have been a build up of pressure. If this is correct that the leak is a sympton rather than the cause. I need a G3 plumber? The megaflow has a phone no on it - Should I call them or a normal plumber?

keystone

joepubli wrote: »

there IS a pipe leading away from the red valve. It follows the oveflow out of the building.

That would be the 22mm one then that comes out of the rear of the top of the valve, turns right and heads into a sleeve behind the Megaflo then? When you say "follows the" does that mean join up with so that it vents to the outside or just run alongside and join up with another pipe somewhere else?

If this is correct that the leak is a sympton rather than the cause. I need a G3 plumber? The megaflow has a phone no on it - Should I call them or a normal plumber?

A leak is always a symptom of something else happening.

You need one with a G3 ticket if theres work needed on the unvented cylinder. A "normal" plumber could fix your pump problem for you and check your EV. If the telephone number on the unvented is that of the installer (which it probably is) then using him/her might be a good plan.

Cheers

joepubli

Thanks

keystone wrote: »

That would be the 22mm one then that comes out of the rear of the top of the valve, turns right and heads into a sleeve behind the Megaflo then? When you say "follows the" does that mean join up with so that it vents to the outside or just run alongside and join up with another pipe somewhere else?

I have follow it and it goes along with the overflow pipw from the Megaflow out of the building. So I suspect if there is water in it it discharges outside

keystone wrote: »

A leak is always a symptom of something else happening.

You need one with a G3 ticket if theres work needed on the unvented cylinder. A "normal" plumber could fix your pump problem for you and check your EV. If the telephone number on the unvented is that of the installer (which it probably is) then using him/her might be a good plan.

Cheers

Yes that's my fear that it signals something else. a few weeks ago the heating stopped working and it was because of loss of pressure. I repressurised it and it worked fine.

Then yesterday I have this leak from the side of the pump - I think there must have been build up of pressure to cause it. Unfortunately no number for the installer on it .The number is for Megaflo and they say they can't help with the pump. I have a plumber coming this afternoon.

joepubli

Keystone and Canucklehead
Many thanks for your help. Had a plumber round to sort out the leak from the water pump - completely worn washers on BOTH sides!
He fixed that and its now working fine.

Thanks to you, now I understand what was wrong rather than just have it fixed without having a clue.