Megaflo - what alternative cylinder brands do you recommend?

[Harry Flashman]

Chaps, so the 250 litre Megaflo I inherited with our house is scaled up and wrecked, and needs replacement. I would like to replace it.

Now Megaflos have an integrated expansion vessel, but I know other cylinders do not. Also, the Megaflo has proved to be an absolute pig to use with Honeywell Evohome, as it does not have a dry sensor pocket for the sensor required to monitor the hot water temperature.

Given that I have the space for an expansion vessel or two above the Megaflo’s cupboard, what brands would you recommend? I am not worried about brand name – I am more worried about reliability and ease of maintenance, and warranty.

House is 5 beds, 3 baths, with a Worcester Classic 35CDi system boiler (brand new).

Any tips appreciated -= I have to buy a new cylinder for fitting next week.

[s1962a]

We have the Vaillant Unistor.. seems to be fine - no issues with it and it pairs up nicely with vaillant control centres.

The only problem i've found now is that the Vaillant 'ebus' system that controls the boiler and the Unistor isn't compatible with Hive, Nest or any of the other automation brands out there right now.

[essayer]

The Vaillant seems a good bit of kit, and it has the all-important pocket for the NTC thermistor, and sensible wiring on the outside for the cylinder/overheat stat.

[Harry Flashman]

Thanks guys. Looks like Worcester also have a sensor pocket, as do Gledhill, recommended by my builder who says that whilst they are cheaper than the "known" brands, he has never had a problem with one, and has installed a load. Any more thoughts?

Whatever it is, the boiler is already running Evohome controls, so the cylinder is just a hot water storage unit, with an immersion heater for emergencies. No need for manufacturers' own control systems.

[guindilias]

I've specced Gledhill many times for projects - I see them as just as good as Megaflo. But sometimes clients who know a "little" bit about Megaflo will insist on a Megaflo at twice the price, because they're virtually a household name amongst DIY people, and therefore "Must be the best".
Ah well, it's their money...

[PaulW21781]

I have a Megaflow unvented cylinder with an S-plan setup all controlled via Evohome without issue. I agree, it was somewhat annoying that I couldn't use the insertion sensor in the same location as the safety override.

We ended up contacting Heatrae Sadia about possible solutions, and they said that for regulations, we couldn't disable or modify the existing safety systems (their own insertion sensor & thermal override which if triggered cuts the power from the BDR91 to the hot water valve, and as such cuts demand from the boiler for that side of the loop) however, to fit the CS92 (as it comes with both a strapon and insertion sensor) then it was OK to cut a small square on the outer steel insulation jacket & attach the strapon sensor that way as then it's in contact directly with the cylinder wall.

[olimain]

I have a Telford Tempest - no complaints at all so far, lifetime guarantee

[Rosscow]

What about Joule?

[Harry Flashman]

PaulW21781 said:

I have a Megaflow unvented cylinder with an S-plan setup all controlled via Evohome without issue. I agree, it was somewhat annoying that I couldn't use the insertion sensor in the same location as the safety override.

We ended up contacting Heatrae Sadia about possible solutions, and they said that for regulations, we couldn't disable or modify the existing safety systems (their own insertion sensor & thermal override which if triggered cuts the power from the BDR91 to the hot water valve, and as such cuts demand from the boiler for that side of the loop) however, to fit the CS92 (as it comes with both a strapon and insertion sensor) then it was OK to cut a small square on the outer steel insulation jacket & attach the strapon sensor that way as then it's in contact directly with the cylinder wall.

This is exactly what we did, but I really don't like messing with the insulation - it's a bodge as their cylinders have a stupid design flaw!

[Buzz84]

Rosscow said:

What about Joule?

We have a Joule Cyclone 300L twin coil cylinder that was installed as the tank of choice by our installers. its only been in since last July but has been absolutely fine in that time. It also has dry sensor pockets on it.

[21TonyK]

Don't know if these would fit the bill but two 300l I put in 15+ years ago are still working as per day one.

http://www.osohotwater.co.uk/

[Buzz84]

Also bear in mind that the Megaflow range is made by Heatrae Sadia, but they also sell their own non megaflow branded unvented cylinders that are cheaper!

Here are two comparisons:

Megaflow:
https://www.plumbnation.co.uk/site/heatrae-sadia-m...

Heatrae Sadia:
https://www.plumbnation.co.uk/site/heatrae-sadia-p...

[HotJambalaya]

Just been debating this myself. Getting a quote, and they guy said the megaflo alternative is about half the price but has the expansion vessel on the outside, apart from that he says its every bit as good.

[olimain]

HotJambalaya said:

Just been debating this myself. Getting a quote, and they guy said the megaflo alternative is about half the price but has the expansion vessel on the outside, apart from that he says its every bit as good.

I considered the expansion vessel on the outside to be a plus rather than a minus. I researched a lot when I was doing ours and came to the conclusion that with Megaflo I would just be paying double for the name more than anything else.

[Pickled Piper]

Gledhill support, should you have a problem, is appalling.

Have had an OSO for more that ten years. No issues.