Leaking Megaflo?

[Steve Roberts]

Hi -my megaflo system is 18 years old, and over the past weeks I have become suspicious that it is "leaking" due to mould forming in the ceiling of the cupboard underneath the airing cupboard where the cylinder is.

Some possible sources of the mould: cold water pipes run down through open holes in the floor of the airing cupboard carrying condensation from drying clothes, into the void. But this is a new problem and we've not changed our drying habits. I've now blocked up the gaps between the floor and the pipes with sealant, but while it's possible this is the cause, I'm not convincing myself.

It seems the overflow has been dripping for a while, so I've regenerated the system. But is it possible that an unregenerated system could be more prone to leaks around the cylinder and I've just not noticed it?

Or maybe the cylinder is leaking from somewhere else inaccessible. Is there a way to tell without ripping it out at great expense? I have no feel for how likely this is after 18 years...

Any ideas?

 

[Newboy]

May be water vapour from the combined relief valve condensing or the discharge (dripping) hasn't made it's way down the discharge pipework and has instead been running along the pipework and into the void.

 

[Steve Roberts]

The discharge normally goes through the tundish right? The genius who installed this put the tundish in the far corner where you need the agility of a trained lemur to get close to it. (Raises a question about how it was installed in the first place in the absence of certified lemur installers, but we'll let that pass...)


PART 2 of this post: with the aid of a torch, knee pads and with the chiropractor's emergency contact details in my back pocket I ventured deep into the confined space. Didn't find any Malaysian footballers there, but did discover a very damp floor, and somehow, with scale buildup, the water was running along the arms of the tundish and down the outside of the pipe to wet the floor - soak it in fact. You were spot on, @NotSoNewboy! Thank you. So now to stop the drip, which I'll try again by regenerating the bubble. I thought I'd done that, but perhaps not well enough.

 

[Newboy]

The discharge normally goes through the tundish right? The genius who installed this put the tundish in the far corner where you need the agility of a trained lemur to get close to it. (Raises a question about how it was installed in the first place in the absence of certified lemur installers, but we'll let that pass...)

yes - sometimes, where scale builds up and the discharge is continuous low volume the discharge can run outside the tundish

 

[muggles]

The original tundishes are notorious for dribbling all over the floor. There's an updated design, but of course you need to be able to get at it to change it! The stupid floating baffle system inside Megaflo cylinders often fails as well, so regenerating doesn't always work.

 

[snb]

it may well be better to get a qualified G3 installer to check it over, could be many causes. pressure reducing set allowing pressure too high, leaking T&P valve, leaking PRV, failed baffle. if it is just the baffle then cheapest option is to fit an external expansion vessel.

 

[endaxi]

..... failed baffle. if it is just the baffle then cheapest option is to fit an external expansion vessel.

..... The stupid floating baffle system inside Megaflo cylinders often fails as well, so regenerating doesn't always work.

Hi,

Sorry to butt-in on the thread but I'm having problems myself and am trying to understand how these Megaflo systems work. I'm going to try to regenerate my air gap when I get the opportunity. I wanted to do it today but will probably have to wait until tomorrow. Can either of you please explain what the floating baffle actually is, what it does and how you would know if it has failed?

Also, my cylinder is a 15 year old Megaflo CL210 and I can't find any reference to a floating baffle in the handbook. Is the baffle a recent addition and is it possible that my tank doesn't have one?

Thanks.

 

[muggles]

The baffle is as per the below picture - it's a disc the width of the internal cylinder which separates air (above) from water (below). When the water is heated, it expands, and the baffle is forced upwards, compressing the air above it and maintaining a constant water pressure in the cylinder. The air above the baffle escapes over time, and the air gap should be regenerated as part of the cylinder's annual service, but as only 0.0000000001% of unvented cylinder owners actually bother to get their cylinder serviced annually, this is almost never done, and some owners find they have to regenerate more frequently than that anyway. The system also stops working properly if the baffle gets stuck, dislodged, punctured, if Uncle Bob's birthday is on a Tuesday, or if it remembers its former life as a giant frisbee. As you can probably imagine, any hint of limescale on the dip tube it is supposed to slide up and down will immediately render it even more useless than it already is. You will then require the services of a G3-registered person, who can fit some bits to circumvent the need for the baffle, although if you're unfortunate enough to have a baffle that is stuck right at the top of the cylinder, you'll find that you start using more energy to heat your water, because the hottest water will sit in the space above the base of the dip tube/baffle guide (normally filled with air) never actually being used because it can't get out, so you have to turn your thermostat up to compensate.

Sorry, that was a bit of a rant. I think it's a stupid system, and yes your old Megaflo does have one. It's their unique selling point. They invented it, and they're damn well going to keep using it!

 

[Steve Roberts]

Thank you for all your observations and enthusiastic reviews of the Megaflo system. Since the system had become as incontinent as a close family member with a prostate issue, I ended up wrapping some Jcloth around the pipe below the tundish, securing it with cable-ties, and then feeding it into a plastic bottle so as to direct the leak away from the floor. It worked a treat - I would patent that solution if I could. But where was the leak coming from in the first place? I recently had a pressure vessel replaced (sorry if that's not the correct banter: it's a container with a valve and dial that supposedly keeps the rads topped up); the valve is new and when you turn it, water rushes out through the tundish. So I tried turning it to watch the pretty flow of water through the inaccessible tundish, then releasing it, and behold, there remained a drip. But then I did it a second and third time, and after I did that, the drip did not return. So my amateur diagnosis is that this new valve needed a bit of seating in - perhaps had a bit of scale or something stuck in it.
Now the drip may be biding its time until we've forgotten about it, and, like a dose of something unpleasant, will return when least expected. But this time, the Jcloth-cable-tie-plastic-bottle will thwart it.
Thank you again - it's been fun, I hope we've all learned something.

 

[endaxi]

The baffle is as per the below picture - it's a disc the width of the internal cylinder which separates air (above) from water (below). When the water is heated, it expands, and the baffle is forced upwards, compressing the air above it and maintaining a constant water pressure in the cylinder. The air above the baffle escapes over time, and the air gap should be regenerated as part of the cylinder's annual service, but as only 0.0000000001% of unvented cylinder owners actually bother to get their cylinder serviced annually, this is almost never done, and some owners find they have to regenerate more frequently than that anyway. The system also stops working properly if the baffle gets stuck, dislodged, punctured, if Uncle Bob's birthday is on a Tuesday, or if it remembers its former life as a giant frisbee. As you can probably imagine, any hint of limescale on the dip tube it is supposed to slide up and down will immediately render it even more useless than it already is. You will then require the services of a G3-registered person, who can fit some bits to circumvent the need for the baffle, although if you're unfortunate enough to have a baffle that is stuck right at the top of the cylinder, you'll find that you start using more energy to heat your water, because the hottest water will sit in the space above the base of the dip tube/baffle guide (normally filled with air) never actually being used because it can't get out, so you have to turn your thermostat up to compensate.

Sorry, that was a bit of a rant. I think it's a stupid system, and yes your old Megaflo does have one. It's their unique selling point. They invented it, and they're damn well going to keep using it!

Thanks very much muggles. Great explanation. let's hope my baffle still rises and falls as it should.

 

[Razor900]

Last megaflop I went to like that was sitting on chipboard without any additional support under it and damned near went through the floor!

Not wishing to be alarmist but I'd be checking very carefully.....

 

[Steve Roberts]

Thank you Razor900 - yes, that's a worry isn't it? It's going to be quite a job to inspect the floor though -still thinking about how to do that. I can take comfort in the thought that if it crashes through the floor it's unlikely to fall on anyone, except perhaps the cat if he's sleeping in the cupboard again.
But sadly, the fix was temporary: I regenerated the system as per instructions, but we have a very very slow drip now, which is running at 200ml per day, collected by my wicked bottle (using a wick I mean). So much better than before, but there remain two issues: the tundish isn't doing its job and it needs retraining or replacing, and the drip is unwelcome and needs resolving. I think I'm at the point of calling in the professionals, but until then, let's deal with the tundish. Because of the location, and now a trapped nerve in my shoulder, it's proving difficult to extract. My thinking was to remove the limescale with descaler so at least the drips stay inside and don't wriggle their outside down the pipe.
So, any tricks or thoughts on how to deal with recalcitrant tundishes - the ones where the water drips run down the outside?
(Also bought a leak detector from eBay - hopefully we won't leave the leak unspotted next time.)

 

[Newboy]

To be honest, fixing the dripping tundish is tackling a symptom rather than resolving the cause.

Get a G3 ticketed plumber in, sort out the cause of the discharge and at the same time replace the tundish with one that works as it should.