Boiler queries - Worcester Bosch Compact

[mo7]

I have been trying to decide on what boiler to go for - I think my head is about to explode - but I have to make a decision.

Some background - I have a combi boiler - 4 bedroom house with 9 radiators (of varying sizes - 3 big doubles and the rest singles)

My current boiler is an Aristion Clas HE with 24kw output and 10.3 water flow rate.

The current boiler has been fine for central heating/radiator purposes but average for hot water. I am replacing the boiler and moving it to a new position and will be running a shower off the boiler instead of the current electric so concerned about water flow rates.

After much faffing I have decided to go for a Worcestor Bosch. My decision is between the normal sized 34CDi and the Compact 36 or 32.

The stats:

34 CDi - 30kw and 14.3litres
32 Compact - 24kw and 13.1 litres
36 Compact - 24kw and 14.7 litres

I wanted to go for the Compact because they fit in a kitchen unit and long story short the perfect place is in a kitchen unit right near where the mains comes in. If I go for the 34CDi I will need to move it elsewhere which will cause me a lot of hassle in having to get units in for the kitchen and shifting the kitchen around.

So my first question is - do I need the 30kw or can I stick with 24kw. I am retaining the same radiators (maybe even losing a small one). If I can get by on 24kw then I don't think I need to upgrade. I did an online calculator which suggested I needed just over 6kw for my central heating. I understand the 24kw is the maximum and only some is for the central heating - rest is for the domestic hot water.

I understand that the KW does not make any difference to the actual heat of the CH or HW.... is that right? As it is the boielrs get hot enough and quick enough.

I also understand it might be less efficent/economic to buy an overpowered boiler.

So it looks like I can keep 24kw and go for one of the Compacts - anyone have any thoughts on this?

The only issue is if I decide to get another 10 radiators and then I might be underpowered but this won't happen.

Next question is do I go for the 32 or 36 compact. Default answer seems to be the 36 - just because it has a higher flow rate and I believe if my mains is good enough then this will give me the best shower (do have good mains pressure).

I understand combies are not ideal for running multiple taps, but if you have a combi with a higher flowrate will this help if you are running a shower and someone puts a tap on?

Is there any other reason why it is better to buy the 32 over the 36?

Anyone have experiences of the Compact range? Search does not bring much up.

I have had a boiler guy around for a quote and he has recommended the 32 Compact for the following reasons. 1) fits in cupboard and 2) appears powerful enough. We did not really go into flow rates so I assume he thinks the 32 is good enough for a shower. I initally wanted the 34CDi but I think he has convinced me the Compact would be better (it being much easier to install in the space I want). I will be getting 2 more quotes anyway so can discuss this further but grateful for any views beforehand.

3 people live here but I also want to future proof it for potentially 5 in future (although not sure why a bigger boiler would make much difference as we woudl still have the same number of radiators and 1 bathroom - only thing I can think of is more demand on taps at the same time - hence a bigger boiler now will cover that issue).

 

[Ermintrude]

Sorry I'm out. Can't bring myself to aid the sale of a Worcester .

 

[albatross]

Put the 36 in then you will never regret making the decision. All models run to suit their load so it's not like they run at max power when on. it chooses to do between 7 and 36 kw as required. It will not be any more to run. You are over thinking this quite alot.

 

[mo7]

I looked at Valliant but apparently they don't do one that fits in the kitchen cupboard.

 

[Killy Bing]

If you are looking to future proof for an additional bathroom then go for a system boiler and an unvented cylinder if pressure and flow rates are good.

you say about over sizing boilers, a 24 kw boiler is well oversized for most heating purposes domestically .

a combi is sized on the hot water demand, bigger is better IF you have good enough flow rates. If you get a flow rate of 9 litres per minute then anything above a 24kw is wasted.

Why not keep the existing boiler location?

And why worcester?
Other than their tv ads and marketing


Ideal logic plus boilers have 7 year warranty, kitchen unit fit size and at lower prices.
more boiler for your money and comparable in quality at the middle of the market.

p.s neither the Worcester's or the ideals are my choice of boilers....
thats an impartial view

 

[Ermintrude]

Kb your too good! Ideal all the way. 35kw logic plus.

 

[Killy Bing]

Kb your too good! Ideal all the way. 35kw logic plus.

You said you were out

i won't harp on about my boiler choices.
then again they wont fit in a kitchen unit...

 

[mo7]

We went from a tank style system to a combi about 6 years ago - I thought combis were all the rage from an efficiency perspective.

Old boiler needs to be moved out of a bedroom to make storage space and I am doing the kitchen up anyway so it is ideal to move it into a kitchen and even mroe dieal to get it into a small wall cupboard.

As for Bosch - just chose them based on reading reviews etc. I've spent enough time I want a Bosch Compact that I am not going to reconsider another one! Plus I have made appointments with Bosch approved installers now. Either way I doubt Bosch is the worst and even if other makes are better I imagien the Bosch is good enough.

I'd never even heard of WB until I started looking into a new boiler.

In terms of future proofing I meant if we have more people - so more liekly to have someone using upstairs and downstairs taps as oppsoed to a whole new bathroom.

 

[Killy Bing]

With a platinum installer they can offer you the 7 years the same as ideal but still, higher price tag.

35kw ideal will come in less than a 32kw compact by quite a bit.

a little food for thought

could be an idea to post up your location on here and ask members to get in touch to give you quotes.

 

[AWheating]

WB are good boilers. Most of us plumbers are bias when it comes to recommending a boiler make and model tbh. WB will honor the warranty without issues (bar really bad installation) and wont sell your details to national companies. get it installed by a company that offers the 7 year warranty and wants to service it yearly for you. Normally if they are planning to service it for years after they will want to install it correctly.

you gas pipework will more than likely need upgrading to a larger pipe size also.

as for the output if your cold water suppply is good enough then go for the larger size. Its pointless going for a boiler capable of running at 14lpm temp rise when your cold is only coming in at 12lpm.

the installer can adjust the boiler in the software to suit the central heating demand to avoid it firing on full rate.