Unvented Hot Water
- Thread starter jon26
- Start date
B
BigBurner
What is the best HW cylinder available please. I am looking at unvented and could do with one that is able to reheat quickly.
Jon
Look at a heat bank/thermal store. They can also do the CH as well offering CH buffering - they do much more. Unlike an unvented cylinder, It doesn't have the qualities of TNT.
What i'd ask is what is the best for me, as all unvented cylinder manufacturers bring something to the party as in price, overall unit size, actual capacity, recovery time and ease of installation. Reliability is not really an issue anymore as most are constructed the same way and offer a 25yr guarantee. Personally i'd steer clear on thermal store systems as i have found that relibility is the main problem, especially in hard water areas
B
BigBurner
A good one is NOT cheap.
Largish
Which is poor as the makers do not like the pressure to rise too much. A lot of kW very quickly raises the pressure far more.
Which is quite the opposite to my experience. They also give important CH buffering and enable TRVs on all, rads using a Smart pump. Boiler cycling is eliminated. Some models don't even have overflow pipes and can be fitted in the middle of a house. Rads instantly hot first in the morning. And they do not have the qualities of TNT when vented.
No contest stores with plate heat exchangers (heat banks) win. Unvented cylinders are a marketing ploy which worked. It made people believe it was something it wasn't.
Remember you need and annual service with an unvented cylinder. For that reason alone I would avoid them like the plague.
I can only think of specialist applications where unvented cylinders would be appropriate.
B
BigBurner
A cheap, efficient and safe way of have high pressure hot water. There are superior alternatives around that are not akin to TNT.
One of the fastest to reheat is the ACV SLE range. You will need the SystemPAK accessory.
It can also store more useful hot water Kw than a normal unvented because it is designed to run the HW up to 85C if you choose.
It can also store more useful hot water Kw than a normal unvented because it is designed to run the HW up to 85C if you choose.
Unvented cylinders were invented here in GB and used extensively though out the world, now we are "allowed" to use them!
I prefer a cylinder with external expansion vessel, as when the diaphragm goes its easy to replace. If the "baffle" plays up on a Megaflo(some other brands as well) its a pain!
Where does Big Burner get all this stuff about TNT. If they are installed by someone that is trained/experienced to do so, little can go wrong.
Bit like saying gas boilers and fires can be TNT so don't install them either??
I prefer a cylinder with external expansion vessel, as when the diaphragm goes its easy to replace. If the "baffle" plays up on a Megaflo(some other brands as well) its a pain!
Where does Big Burner get all this stuff about TNT. If they are installed by someone that is trained/experienced to do so, little can go wrong.
Bit like saying gas boilers and fires can be TNT so don't install them either??
D
Deleted member 105431
Vaillant do a 25yr guarantee on the unistor range which has an external exp vsl and very quick reheat time. Does not req an annual service and has twin immersion heater option on larger cylinders.
i haven't been called to repair a single one that was fitted by someone with correct knowledge or will to apply correct knowledge. They have never been serviced. That's why.
Sounds like gas boilers then! Every joe seems to put them in on the quiet and everything is sweet until something is overlooked
BANG!!
People seem to think a "service" is con to get money out of them??
Thanks simond,
My thoughts exactly, their tank-in-tank system allows a much quicker reheat time also they are able to re-heat quicker due to the larger kW boiler intake.
The water can be mixed down from 85degC = more HW
Also as an installer I was very impressed by the way the mfc valve tpr ev etc were all jigged up for you on top of the cylinder. With the obvious labour saving benefit the neatness factor and the less obvious benefit that D2 pipework starts higher up allowing more locations for the cylinder.
Yes a very good choice.
OToH I got a few year old 145 litre megaflow bubble top for £135 on ebay.
You pays your money you takes your choice.
Yes a very good choice.
OToH I got a few year old 145 litre megaflow bubble top for £135 on ebay.
You pays your money you takes your choice.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local