Switch to Megaflo

[anonymouse91]

Hi,

We currently are in the process of a loft conversion and have been advised to install a Megaflo system to replace our current Combi system.

Our current system is a Gloworm Combi Boiler which doesn't usually go above 2 bars.

After the building work, we will have 3 bathrooms (one with bath and 2 with showers)

From what I have read, we will probably have to change the system due to the amount of bathrooms and as there are 2 adults, 2 teens and 1 child in the house (high usage)

Could anyone recommend any Megaflo systems along with a large cylinder?

 

[Breesey]

What's your mains flow and pressure?

The choice of cylinder is yours. I like Oso.

 

[anonymouse91]

What's your mains flow and pressure?

The choice of cylinder is yours. I like Oso.

Thanks for your reply.

Sorry for being a pain but I have no idea how to find out what the pressure and flow is. How can I check this?

I can give you a bar reading of the boiler when on if that helps.

 

[ChrisR]

YOu need a pressure gauge (£8 - 15 or so)

to measure the pressure though the day, and to measure the flow from the mains - add kitchen sink and outside tap flows when on together.

 

[Breesey]

I can give you a bar reading of the boiler when on if that helps.

That won't help at all!!

As ChrisR says, you'll need a gauge that you can attach to a mains supplied outlet. If you have an unrestricted tap then time how long it takes to draw off one litre and that will give you a good enough idea of your flow.

 

[Balenza]

Avoid the megaflo or any other UV cylinder for that matter as they have the potential to do this........................

http://www.youtube.com/watch?v=akqvaZ5J1aY&feature=related

 

[anonymouse91]

Thanks. I'll try and get a gauge sometime this week. I'll post back when i've got the reading.

 

[Doctor Drivel]

Avoid an unvented cylinder they can blow up. Get a superior failsafe heat bank.

They can do this if improperly installed ....
http://www.youtube.com/watch?v=GF_Wrm-Ns0I

and this...
http://www.youtube.com/watch?v=akqvaZ5J1aY&feature=related

Look at:
//www.diynot.com/forums/viewtopic.php?p=500815#500815

 

[billy bob]

Not according to your other post's Doctor Drivel, where you recommend the use of the Vitodens 333, and the Alpha CD50, both these units contain unvented cylinders, you clearly have no idea, I advise the OP to ignore anything Doctor Drivel posts

 

[billy bob]

Ignore Doctor Drivel's post, unvented cylinders are perfectly safe, the UK add more safety devices than any other country, not one unvented cylinder has exploded in the UK, Doctor Drivel has been asked to show factual evidence of any such explosion happening, he can not, he simply refers to the links he has posted where cylinders have had all safety systems blocked and are carried out under extreme situations, none are in a house, the only type of system that has caused damage and unfortunately deaths are the vented system, to which Doctor Drivel refers to as fail safe, there are a couple of high profile instances of this happening.

 

[Nixt]

Not according to your other post's Doctor Drivel, where you recommend the use of the Vitodens 333, and the Alpha CD50, both these units contain unvented cylinders, you clearly have no idea, I advise the OP to ignore anything Doctor Drivel posts

Much the same is being said on the Screwfix forum.

 

[Nixt]

Do you what unvented cylinders can do. Have you looked at the links to youtube? Are you in this game? You clearly don't understand,.

Sounds like the OP needs someone who understands cylinders. Imagine if they decided against an unvented HW store because of safety fears and then trusted some complete charlatan who offered say the Alpha CD50 thinking it works like a heat bank.

 

[Nixt]

Do you what unvented cylinders can do. Have you looked at the links to youtube? Are you in this game? You clearly don't understand,.

Sounds like the OP needs someone who understands cylinders.

That;s me, not the cowboys of which there are far too many on this forum.

Or charlatans that mistakenly offer the OP the Alpha CD50 as a heatbank

 

[billy bob]

DD your links are irrelevant, the cylinders are not in a house under normal use, I could make anything explode if I wanted to, you say that people have the right to see dangers that can kill, well show us somewhere in the UK where someone has been killed by an unvented cylinder, otherwise stop scaremongering, either PROVE your statements or stay quiet, your links to silly videos of set ups does not count as evidence.

 

[WDIK]

unvented cyinder and calorifiers sold in this country are perfectly safe because they have meet some of the highest design standards in the world.
they are supplied with all the correct safety devices
unvented cylinders must be installed by G3 qualified and registered installers, all repairs and servicing must be undertaken by G3 qualified and registered installers.

an unvented cylinder is a pressure vessel and as such carries the danger that all pressure vessels carry.
so therefore they are fitted with safety devices that are designed to
FAIL SAFE

The problem with unvented hot water cylinders is that the water gets hot and when water gets hot it expands,
so it will have an expansion vessel fitted.
because the expansion vessel might fail they then have a safety valve.
however the greatest danger with an unvented cylinder is that if the control and high limit stats failed the the temperature could rise to above 100 degree's C, as we know water turns to steam at that temp, and water from say a tap could turn to steam.
if the vessel were to rupture under such circumstances then as the water turned to steam then the rapid expansion to steam would cause an explosion.
so the vessel is pressure tested and certified to 15bar and batch tested to
30bar.
a pressure reducing valve is fitted to the inlet water to limit the pressure to 3bar.
so the next level of protection is by an ingenius device as pictured below.

this thing is The Temperature and Pressure Relief Valve It is pre-set to open at 7 bar (101.5 psi) and 90ºC.

what that in effect does is if the temperature exceeds 90c then it opens and a miracle happens the hot water is released to waste and as a result of this cold water enters the vessel and cools the water down, preventing the water boiling.
very often and as in the case of the Megaflo this comes as a combined safety valve.

as for the question of has an unvented cylinder ever exploded in this country the answer is technically no..
however...

there was an off shore explosion on the 16th of april 2000
aboard a fishing vessel call the fleur de lys, it sank 18 miles off portland bill.
as a marine accident there was a board of enquiry and the results were published.

you can be sad like me and read it
http://www.maib.gov.uk/cms_resources/fleur-de-lys.pdf

the upshot is that the cylinder was fitted with out the safety devices and the cylinder shell was of inferior quality.