Megaflo dripping

[tonyblack999]

Hi, I have a Worcester boiler and a Megaflo. Everytime the hotwater or heating turns on the megaflo drips into the tundra and outside through a copper pipe. We are only getting enough hotwater for 1 shower!
I've just moved into the house, but I believe the whole system is about 2 years old.

I've tried recharging the megaflo as per instructions. I close the cold water supply and turn on the lowest hot tap, but when I open the PRV only a trickle of water comes out (about 300 ml) and quickly turns into a drip.

I've added images if this helps. Thx for any advice!


View media item 25117View media item 25118 View media item 25119 View media item 25120

 

[twgas]

I would suspect that 1 or more shower/mixer tap is passing, letting cold water into the hot pipe/tank as there does not appear to be a balanced cold supply.
Can you isolate any supplies to the shower(s), if so, try doing this to one pipe to eachmixer at a time then run other hot taps and let us know what happens.

 

[tonyblack999]

thx Mick, what do I need to do to isolate each shower?

 

[tincup]

Hi

A loss of expansion volume would be my first thought.
However unvented cylinders can be dangerous.


Get someone to look it over who as the unvented ticket.

 

[twgas]

thx Mick, what do I need to do to isolate each shower?

find iso valves on the pipework and turn them off.

 

[Axel]

It has been known for a Megaflo to fail to hold its air charge, even after re-charging.

One solution (suggested by Heatrae Sadia) is to fit an external expansion vessel to the system, to prevent the pressure rising high enough to escape through the safety valve.

Could also be a safety valve letting by.

 

[wetshoes]

Faulty temp/pressure relief valve

 

[OwainDIYer]

a tundish is a small funnel with a pipe discharging into it immediately above. It is used to provide an air break in overflows etc., preventing possible backwards contamination.

Tundra is a treeless region near the poles of the Earth, or at high elevation

 

[twgas]

a tundish is a small funnel with a pipe discharging into it immediately above. It is used to provide an air break in overflows etc., preventing possible backwards contamination.

Tundra is a treeless region near the poles of the Earth, or at high elevation

If you go through this site correcting all the spelling, grammer etc you'll never have time to post anything useful, us G3s new what he (or she) meant.

 

[snb]

from what you have said you have failed to re create the air bubble.

follow the instructions on the side of the cylinder.

close off cold supply
open hot tap
when water stops open pressure relief valve (on side of cylinder 2/3 rds way up cylinder with balck or blue knurled nut.

hold this open until the gurling sounds stop. this can take 10 mins.

should solve problem.

have had this problem on most megaflows. normally within a year of fitting and this needs to be done every year.

 

[AWC1]

I agree it seems to be a faulty TPRV.

What happens is as the water is heated the TPRV lets out hot water from the top of the tank and cold water is filled from the bottom again, this only giving you enough water for one shower.

If it was a pressure problem the 8.0 bar Pressure Relief Valve should open and let out water from the cold inlet side not usually affecting the amout of hot water in the cylinder.

One way to be certain which valve is leaking is by checking the water running through the tundish, if it is hot then its the TPRV if its cold then its the Pressure Relief Valve (this is assuming that the water inside the tank is hot)

You will need a G3 certificated plumber to install this valve but you can google for the item, looking at the pictures you have a " TPR15 10 Bar " if you google that you should be able to find the part you require.

Hope this helps.
Richard