megaflow, twist or stick

[bolst3r]

In short, a 13yr old megaflow (CL210HE) failed a while ago, as it appeared the baffles were breaking down. Megaflow accepted a fault and supplied a new replacement (inc all the fitting kit and MV). So I guess i'm one of the lucky ones...

But i've lost confidence in the product, I felt I was buying the best at the time but it seemed to always have an issue because it needed recharging ever 6-8wks. Maybe it had a problem since new and I never realised?

I've had a couple of plumbers around and i'm not sure which way to go, one plumber says they are sh*t, another says his own has been faultless for over ten years and i've had the two following suggestions:

1. Fit the replacement megaflow (all the pipework is in the correct place, I have the tank and everything I need here)
2. Fit something like a RM Stelflow 250l (will need to adjust more of the pipework, and make room for the external expansion vessel)

Obviously the advantage of fitting the warranty replacement is I have the product, and it's like for like so minimal work/cost. The disadvantage of the Stelflow is the cost to purchase and making space for the external expansion vessel. I know I can slightly off-set the purchase cost with the sale of the megaflow.

So should I stick or twist?

 

[MickyP10]

I'm no plumber but I'd stick. Never had an issue with pressure, etc, in three years, and this was a 10-year-old unit when I moved in.

 

[kidgreen61]

Just install a remote exp vessel, you should be ok.

 

[Johntheo5]

I'm no plumber but I'd stick. Never had an issue with pressure, etc, in three years, and this was a 10-year-old unit when I moved in.

Did you ever have to recharge the air bubble in these three years?

 

[Madrab]

Stick ....

It seem that they have solved the baffle breaking down issue in their latest products, apparently it was only a certain type/batch of units that had the issue with the baffle. In their defence they are one of the rare manufacturers that don't actually blame the install(er) in these cases and will actually replace the faulty unit.

I think a new one should last you well and like all of these things, as long as it is installed, benchmarked and registered by a qualified installer and serviced properly every year, then the new unit's warranty will cover any future issues.

 

[bolst3r]

Just install a remote exp vessel, you should be ok.

ah, that's interesting, so I could just get the replacement tank installed, then if it goes again I have the option to add an external expansion vessel?

This sounds a very pragmatic way of dealing with it.

 

[bolst3r]

Stick ....

It seem that they have solved the baffle breaking down issue in their latest products, apparently it was only a certain type/batch of units that had the issue with the baffle. In their defence they are one of the rare manufacturers that don't actually blame the install(er) in these cases and will actually replace the faulty unit.

I think a new one should last you well and like all of these things, as long as it is installed, benchmarked and registered by a qualified installer and serviced properly every year, then the new unit's warranty will cover any future issues.

ok, that's great to hear, and as I have it all here it makes sense to stick with it. TBF to them they replaced the tank without much of a fuss. Perhaps they deserve a bit more of my loyalty

 

[Johntheo5]

Stick ....

It seem that they have solved the baffle breaking down issue in their latest products, apparently it was only a certain type/batch of units that had the issue with the baffle. In their defence they are one of the rare manufacturers that don't actually blame the install(er) in these cases and will actually replace the faulty unit.

I think a new one should last you well and like all of these things, as long as it is installed, benchmarked and registered by a qualified installer and serviced properly every year, then the new unit's warranty will cover any future issues.

Well over 50 years ago I sailed on ships that had a air bubble in the cold water (pumped) vessels (rubber lined steel) but no baffles of any description, you could increase/replinish the air bubble by admitting compressed air into the top of the cylinder, there was a sight glass on the side of the vessel, we maintained a far greater bubble than the Megaflo ( see below) but on 7 to 9 month trips would only have to top up the bubble once or twice, probably because of the bubble volume?.
I took a few dimensions from a 250L Megaflo and the PRV (where the air is admitted) is ~ 432mm from the top, a 62.5L bubble, when/if the cylinder is pressurized to 3bar, the water level is 108mm from the top, a 15.6L bubble and when the cylinder is heated to 60C (pressure 4.28bar) the water level is only 81.8mm from the top, a 11.7L bubble, so (assuming my calcs are anway correct) easy to see the consequences if any air is lost or absorbed by the water.

 

[Madrab]

ah, that's interesting, so I could just get the replacement tank installed, then if it goes again I have the option to add an external expansion vessel

With some unvented the internal baffle no longer hold the air properly and then an external EV can be used, the trouble with some of the Megaflo's is that the internal baffle starts to break down ending up with gooey/plastic type material being deposited and blocking up tap and shower filters, an external EV wouldn't prevent that.

So it all depends on what the symptoms are whether an external EV would work or not ... if you see what I mean

 

[Johntheo5]

Hope the baffle didn't end up like this.

 

[bolst3r]

With some unvented the internal baffle no longer hold the air properly and then an external EV can be used, the trouble with some of the Megaflo's is that the internal baffle starts to break down ending up with gooey/plastic type material being deposited and blocking up tap and shower filters, an external EV wouldn't prevent that.

So it all depends on what the symptoms are whether an external EV would work or not ... if you see what I mean

totally, I think i've likely suffered a bit of this on some of my taps. I have a crosswater where the hot tap is really difficult to turn and it's a discontinued model so I might be screwed not being able to get a replacement...

I was sent a megaflow replacement a year or two ago but didn't install it as the original one was still working and I hadn't decided what to do and was waiting until I did an extension. Now i'm ready to move forward and I think i'll stick with the replacement as it will be easy to fit and comes with a new fitting kit.

 

[bolst3r]

Hope the baffle didn't end up like this.

well, I don't know if mine is that bad but I used to get those deposits when I drained the tank to recharge the air gap.

 

[Johntheo5]

You don't have to drain the tank, if this is what you literally .mean, to recharge the air gap, you just open the PRV and drain until no more water comes out, I don't know how far down the dip tube extends which will determine how much debris gets into the system as its end will be well below the water surface normally once recharged.
For interest, how often did you have to recharge with the failed baffle?.

 

[Madrab]

Just checking @Johntheo5 are you talking about the T&PRV as against the PRV?

If the PRV were to be opened then depending on where the combination valve is located, above or below, there may be very little or the whole cylinder drained out.

 

[Johntheo5]

The T&PRV.