combi to heat unvented cylinder

[ant101]

Hi

Could I use a combi to heat an unvented cylinder to supply hot water to a 230 litre jacuzzi. If I need a recovery time of 30 mins would this depend on the boiler capacity or the cylinder?

What size boiler (combi or not)and cylinder would I need?
Not bothered about the instant hot water flow rate from combi.

How are combi s rated eg 35 kw, is this to heat the CH or the instant HW.
If this is only for HW rating would a conventional boiler of less kw suffice for just CH

Sorry if not making sense
Thanks for any help

 

[mogget]

Are you planning on supplying all your hot water from the cylinder, or the jacuzzi from the cylinder and combi for everything else?

You'll be needing the help of a professional for at least some of this job.

 

[bengasman]

Why would you want to use a combi for that?

 

[BigBurner]

Don't bother with an unvented cylinder, they cost an annual service charge, get your self a high flow combi. Beats the daylights out of an unvented cylinder for DHW delivery.

Now look at an Ethos 54C, 23 litres/min combi or Rinnai multi-point. That is 690 litres in 30 minutes delivered. That is a bath after bath. How long will a 24kW boiler take to re-heat a super large and super expensive 700 litre unvented cylinder? Not to mention the extension built for it!!!

An Ethos would take 10 minutes to fill the jacuzzi. And no recovery time.

No contest. An Ethos or MAN combi, Rinnai Twinflow or multi-point p1ssess all over a cylinder in DHW delivery.

Now look at say W-Bosch 550 stored water combi, which has an integral heat bank. It delivers 25 litre/min while the store is charged. It will dump 180 litres in 3 minutes, then reverts to what the burner gives . 41.1kW is approx 17 litres/min. So, in 30 mins this will deliver 180 litres + 459 = 639 litres. All uninterupted flow. No contest in a combi vs. separate system boiler and unvented cylinder.

A W-Bosch HighFlow 550 costs under £2,000. How much would a 650 unvented cylinder, system boiler and all the controls cost? Ermmmm, Ermmmm.

Combi wins:

1) in installation costs.
2) in space saving (seen the size of a 700 litre cylinder?)
3) in speed of installation.
4) in running costs.
5) in DHW delivery.

http://www.rinnaiuk.com/Updates-18-09-08/A4 Twin Flow.pdf
http://www.ethosboilers.co.uk/products_54c.php

 

[Deleted member 105431]

Don't bother with an unvented cylinder, they cost an annual service charge, get your self a high flow combi. Beats the daylights out of an unvented cylinder for DHW delivery.

Now look at an Ethos 54C, 23 litres/min combi or Rinnai multi-point. That is 690 litres in 30 minutes delivered. That is a bath after bath. How long will a 24kW boiler take to re-heat a super large and super expensive 700 litre unvented cylinder? Not to mention the extension built for it!!!

An Ethos would take 10 minutes to fill the jacuzzi. And no recovery time.

No contest. An Ethos or MAN combi, Rinnai Twinflow or multi-point p1ssess all over a cylinder in DHW delivery.

Now look at say W-Bosch 550 stored water combi, which has an integral heat bank. It delivers 25 litre/min while the store is charged. It will dump 180 litres in 3 minutes, then reverts to what the burner gives . 41.1kW is approx 17 litres/min. So, in 30 mins this will deliver 180 litres + 459 = 639 litres. All uninterupted flow. No contest in a combi vs. separate system boiler and unvented cylinder.

A W-Bosch HighFlow 550 costs under £2,000. How much would a 650 unvented cylinder, system boiler and all the controls cost? Ermmmm, Ermmmm.

Combi wins:

1) in installation costs.
2) in space saving (seen the size of a 700 litre cylinder?)
3) in speed of installation.
4) in running costs.
5) in DHW delivery.

http://www.rinnaiuk.com/Updates-18-09-08/A4 Twin Flow.pdf
http://www.ethosboilers.co.uk/products_54c.php[/QUOTE]


You forgot your favourite Remeha avantaplus!

 

[swbjackson]

No remeha are not in this cut and paste. This is cut and paste number 2. Remeha is in cut and paste number 1 where he disses Worcester boilers.

To reply to the OP. Most Combis are rated at 24Kw to heating. The higher rating is for hot water output.

 

[gas4you]

Now look at say W-Bosch 550 stored water combi, which has an integral heat bank. It delivers 25 litre/min while the store is charged. It will dump 180 litres in 3 minutes, then reverts to what the burner gives . 41.1kW is approx 17 litres/min. So, in 30 mins this will deliver 180 litres + 459 = 639 litres. All uninterupted flow. No contest in a combi vs. separate system boiler and unvented cylinder.

A W-Bosch HighFlow 550 costs under £2,000. How much would a 650 unvented cylinder, system boiler and all the controls cost? Ermmmm, Ermmmm.

Combi wins:

W-Bosch are old hat. They are 5 years out of date. I would not touch a W-B, until they get the control system sorted and updated.

Never fail to make yourself look a fool do you

 

[mickyg]

I quite like this one

The Broags are better quality than Vaillant

The Broag 35C is highly rated using the same parts as a Vaillant

 

[Deleted member 105431]

And no mention of a Heat Bank/thermal store/sludge bucket?!

Maybe that is cut and paste no 3.

To the op look at the glow worm ultrapower sxi 170.