Another plea for help with a new CH and HW system thread..

[Dazzor]

Apologies for asking what must be a very common set of questions.

I've been doing a bit of reading on here but am still unsure which way to go really. (flow rates, pressure ratings....I'm getting lost)

I've just moved into a new house and it's got a back-boiler system, tank in the loft and a poorly lagged cylinder stuck in a cupboard in the front bedroom...making the bedroom really hot and uncomfortable.

The system works to a fashion but we want it gone because of the horrible heat in the bedroom and also because we fear it’s not efficient, not to mention the noise it makes behind the fireplace.
Rather than bore you with even more of my guff here’s a list of what we want from a new system .

The House:
• 3 bed semi-detached
• 8 radiators
• Upstairs bathroom with shower (Shower has a 2bar pump..no probs so far, touch wood)
• Intention to extended downstairs in the future and include a second shower & toilet
• All bedrooms and downstairs hall have laminate flooring (harder to access below floorboards)
• Possibility for loft install of combi boiler on decent sized exterior wall
• Tank in loft
• Poorly lagged cylinder in cupboard in main bedroom
• Insufficient space to resite hot-water cylinder in upstairs landing cupboard
• Flow-rate of water unknown as I write this, I’ll do water in the bucket test tonight


What we would like from the system.
• Do away with cylinder in cupboard in main bedroom altogether
• Be able to run two showers to a reasonable level of pressure (simultaneously if poss, not crucial)
• Adjust heating and water temp independently
• Remote control for boiler as we really would like it installed in the loft
• Old back boiler removed.

I’ve been looking at the WB 42CDi…is this overkill for the heating side, therefore less efficient because it keeps going into on/off mode?

Sorry for my total lack of knowledge and using incorrect terminology. I think I’m leaning towards a combi solution because it seems like a simple config and hopefully will help reduced energy bills…won’t it?

Really appreciate any input and info.

Thanks for reading

Darren

 

[kittedup]

If you can get 20l a minute into the house, I would be looking at a heat only boiler with an unvented cylinder on an s plan. Add weather compensation to really get the best out of it.

An unvented cylinder gives negligible heat where it is sited and would easily run 2 showers at once. You could also do away with the noisy shower pump.

Also any components go wrong on an s plan system (pump, valves etc.), you can buy them straight off the shelf in most of the DIY sheds. Anything goes wrong in a combi and you are stuck with using the manufacturer's parts and they are never cheap and can take a while to be ordered.

Ted

 

[Dazzor]

If you can get 20l a minute into the house, I would be looking at a heat only boiler with an unvented cylinder on an s plan. Add weather compensation to really get the best out of it.

An unvented cylinder gives negligible heat where it is sited and would easily run 2 showers at once. You could also do away with the noisy shower pump.

Also any components go wrong on an s plan system (pump, valves etc.), you can buy them straight off the shelf in most of the DIY sheds. Anything goes wrong in a combi and you are stuck with using the manufacturer's parts and they are never cheap and can take a while to be ordered.

Ted

Thanks for the reply, much appreciated.

I'll check the flow-rate tonight..

You say an s-plan...what's that?

Also, you mention a heating only boiler and an unvented cylinder. Does the unvented cylinder heat water using electricity? Won't this cost more to run? Also, is this a Pressurized system thus meaing it will run a shower with 1/2bar pressure?

Thanks

Darren

 

[kittedup]

S plan is the configuration of the pipework. Basically it controls what the boiler heats, water, rads or both at the same time. Type s plan into Google for a diagram.

It is a myth that combi's are cheaper to run. With all the on offs during the day, each time firing at full rate, a combi will use just as much gas as well setup heat only boiler. Put it this way my boiler supplies all the hw my family need in the summer and it runs for 12 minutes a day. In the winter, with the boiler heating the rads anyway, you get hw for free (almost). No combi will do heating and hw at the same time.

The easiest way I find to explain to customers is a combi is a standard catch all package. A well designed heat only s plan system is a bespoke package for your individual needs and can be altered as and when you see fit.

An unvented will run a shower at whatever pressure you have coming into the house. Most are reduced down to 3.5 bar though.

Hope that helps.

Ted

 

[ALEC1]

if this helps I know one install (5 people) that only uses 12kwh per day in summer to heat their hot water (Twin coil cylinder plumbed in series), it will be a bit more in winter...

that is indeed a 24kw combi running @ 10l/m for 30 minutes...yet a combi has to heat up its self or keep itself warm that will be say 20 times a day... thats where combis waste energy.

Combis are suitable where space is at a premium with on bathroom, and you have plenty of that in a 4 bedroom house.

 

[Dazzor]

Thanks chaps, this heat-only with twin-coil cylinder, S-Plan deal sounds very good to me.

Here's the thing I can't get my head round...

I had a plumber round before I posted here (old friend of the family and nice bloke)

Anyway, he looked round and concluded that the best thing to do (because we don't want a cylinder in the main bedroom and the cupboard in the landing is too small was to go for a condensing combi in the loft.

So after a short period of looking online at combi's I found the floor standing WB 440Cdi and was wowed by the litres per-minute and other specs....my man said that apart from the sheer size of getting into the loft and the heat-proofing you'd need on the flooring it was being placed on it would be too heavy with the integrated tank filled with water (about 25 stone i think)

So forgetting all about floorstading combi's as an option (overkill I know) I don't get how this or a cylinder could be too heavy for my loft if I've already got a whopping big water tank up there already...that would be ditched....it would be scrapped with the S-plan option wouldn't it?

This heat-only and cylinder S-plan option.....potentially, could I have this set-up in my loft space?

Thanks again for any advice

Darren

 

[doitall]

Couple of things to consider assuming the mains pressure is ok for a combi.

The pump would have to go.

Don't think you can install the 440cdi in a loft.

If you stick an unvented up there check the floor can take the weight

 

[Dazzor]

Couple of things to consider assuming the mains pressure is ok for a combi.

The pump would have to go.

Don't think you can install the 440cdi in a loft.

If you stick an unvented up there check the floor can take the weight

Thanks.

Yes, I've come to these conclusions too.

1) Combi would be something like the WB42CDi or as good a wall mount as I can get

2) If shower pumps go they go, our mains pressure/flow is quite good I believe, need to double check this for sure though.

Bonuses that i consider include...

A)less noise from loft tanks
B)less noise from Cylinder heating at silly O'Clock in the morning
C) drinking water from any cold tap
D) space reclaimed where old cylinder was


I'm also hearing about Combi's with internal tanks and weather compensation functionality.

Anything right now seems good in comparison to the system I've been landed with in my new house.

I really appreciate all this advice gents...nice forum this.

Darren

 

[Dazzor]

There was more posts and info posted here...where has it gone?

Gutted as I wanted to follow up on some of it.

What gives?

 

[doitall]

If it was one of your posts did you press the submit button.

 

[Dazzor]

If it was one of your posts did you press the submit button.

No, there was a post submitted that suggested "getting hot water for next to nothing was nonsense..(Suggest by another poster on this thread)

Also, a suggestion for a 35kw combi being a viable option and that "someone" would be able to recommend a boiler.

Not sure about the politics on here but I've seen a long thread about a Valliant install where "someone" is getting some serious stick.

I just want unfettered input so that I can consider all the options and opinions on here.

Cheers
D

 

[Dazzor]

Thanks Mod 14.

Makes some sense after reading a few old threads.

I think I've gleaned enough info now to take a more informed approach............which really means I'm even more confused about which way to go than ever. ha ha