Horizontal unvented cylinder - advice!!

[Adrianmole1977]

Hi all, have read a bit on here and thought i would join and do my 1st post..

Hope this hasnt been covered before???????????

I live in a chalet bungalow and has 3 bedrooms up stairs. I have knocked into the spare loft space to put in an on suite and this is where the cold water tanks for the boiler and cold water for the house are located. Vented systems.

I want to remove these and use the space for the on suite and dressing room.

I have a very small standard vented hot water cylinder off a 70k btu boiler.

I want to have once finished 2 bathroom and 2 on suites.

Space is at a premium and i have no room for the standard megaflo vertically or similar makes - i have been told you can get a horizontal one and i am kind lost if these are any good???????????? Or makes??????????

This is goping to be install under the eves - pleanty of space if i know the sizes etc..

I have alot of DIY knowledge and this one is new on me... I have been told and from calcs on the internet that approx 250ltrs minimum would be required....

Any help or questions please ask or post as i think this may be beyond me...

Or does anyone have any better ideas?????

cheers all and thanks in advance for all your help and advice-- great forum!!
Adrian

 

[Dan Robinson]

They are utter shyte. Don't bother.

Your installer should hopefully come up with a better solution than that. A decent combination boiler should do the trick.

A storage combi even better.

You also need to have a special certificate to be able to install unvented cylinders.

 

[Adrianmole1977]

Thanks Dan,

I was hoping that wasnt the case - why do they sell them????

The installer is FGAS registered and Ive checked everything with them about installation - cheers though as i know there are a few dodgy ones out there!!

what size combi would i need???

 

[dcawkwell]

Can't you put an unvented cylinder in a garage if you have one?
Under the stairs?

 

[dumbrill]

They are utter shyte. Don't bother.

What you have said makes no sense. The only thing that can be compromised by having the cylinder on it's side is the effectiveness of the heat transfer when heating. I guess a vertical cylinder would be marginally more efficient. Otherwise providing the cylinder is stainless steel and has a 25 yr guarantee why wouldn't it be OK?

An unvented system is better than a combination boiler anyday.

 

[Adrianmole1977]

i would love to relocate somehwere else but basically no other options..
Its either a combi - which my installer this evening says that the flow rate could be a problem if 2 showers are being run togther.. or an horizontal cyclinder..

Have seacrh and found a Kingspan Tribune one that looks ok, along with the tempest and also a Vienesse ( spelt wrong also) can they all be really that bad???

Cheers for all help!

 

[Dan Robinson]

What you have said makes no sense.

Is there a problem with my English?

They are poor because they are horizontal. A column of water is heated more efficiently and used more efficiently than the equivalent volume horizontally.

Which is why they have to be bigger than their vertical cousins.

Not sure how FGas equates to G3.. but I will happily be corrected.

Yes an unvented cylinder will give a better flow rate (for the duration of its store). But it will take up three times the space of a cylinder fitted horizontally or otherwise.

A storage combi will run two showers adequately (again for the duration of its store/catchup).

What do I know? I only this kind of stuff for a living .

I am loathe to recommend it - but the Vaillant 937 Plus is worth a look-see.

 

[Adrianmole1977]

Sorry dan ment to type gas safe... Doh been a long day!

I have no idea if they are any good or not but on here there seems to be a mixed view... If I have to bathrooms- with 2 baths and another with a shower as well, along with 2 on suites with showers.... Obviously not all at once but two or three showers is a possible, what are my options? Thanks for the advice...

 

[Dan Robinson]

Have you checked your supply to the property can cope with that level of draw?

Gas Safe, does not equate to G3 either... double check their credentials on the GS website and check for Unvented against their list of qualifications.

3 showers could mean 40 odd litres per minute... beyond the scope of most combis admittedly, but I still say to avoid a Horizontal cylinder as much as possible.

 

[Adrianmole1977]

Ok will double check that, just to be on the safe side...
What is the maximum flow rate possible for a combi, without spending the earth,? Cheers

 

[dumbrill]

What you have said makes no sense.

Is there a problem with my English?

Yes, there is a problem with your English; 'utter shyte' is of no help to anyone.

The problem with a horizontal cylinder is due to the lack of depth. There is much less depth to hold the hot layer of water, hence the oversizing. Also more risk of mixing the layers when drawing off the hot. However if there is room to fit the necessarily oversize tank then why not fit one? It's a compromise, but maybe worth considering.

 

[Dan Robinson]

So you want to heat 30 - 50 - 60 percent more water?

Utter shyte.

Clear and to the point I thought. Avoids the swear filter too.

OP, a combi will heat whatever it's gas input will manage. IIRC the highest regular output combi is in the 40kW range so only 15 litres per minute or so at a decent temperature rise.

Storage combis will work differently though.

You will have to compromise somewhere and if fitting a POS horizontal is the only way then it has to be. The phrase that springs to mind though is "you can't polish a tu7d".

 

[Norcon]

Or.. "Its hard to make a silk purse out of a pigs ear"!

 

[doitall]

Nothing wrong with Horizontal cylinder if you have a secondary circuit..

However I would be very concern about sticking a tonne plus in the loft, without expensive structural reinforcing.

I would have thought the best plan would have been a Rinnai instant water heater, it would eat it, assuming of course the mains can deliver 40+ Ltrs/min

 

[Dan Robinson]

We need a Rinnai section in our little project John...