Big house, considering moving away from gas to electric only

[electronicsuk]

Would a large combination boiler have enough oomph to pump hot water around a big house?

Yup

Is warm water underfloor heating compatible with a combination boiler?

Yes, although the flow temperature is usually reduced by a blending valve so that the floors aren't too hot to walk on. If you don't want to have to heat the entire house then this may not be the right way to go, due to the long warmup times involved.

 

[Tweetie]

Is it practical to have some rooms with warm water underfloor heating and some rooms with radiators?

Also, which is the best combi boiler for this?

The Heatmiser system from the earlier link looks fab but expensive, do you know what the average set up cost of a system like that would be?

 

[mickyg]

the normal practice when splitting the system is to have ufh downstairs and rads upstairs. Any decent combi will do what you want for reasonable cost with any generic ufh packs.

 

[Agile]

I would not normally advise a combi boiler for a large house. Although it might be OK for two people a cylinder system is always better and would suit more people if the house is sold.

Tony

 

[Deleted member 105431]

I would not normally advise a combi boiler for a large house. Although it might be OK for two people a cylinder system is always better and would suit more people if the house is sold.

Tony

or a rinnai twinflow or viessmann 222f.

 

[Tweetie]

I hadn't heard of the makes Rinnai or Viessman before, are they as good as Vaillant or Baxi?

I looked up the 222f and it sounds impressive, I also saw the Viessman Vitodens 343-F which has integral solar cylinder and solar control unit. Don't know how much they are though, I couldn't find out on Google so far - are they rare?

On the Rinnai twinflow website it says that hot water storage tanks are expensive to run - does having a combi boiler save significantly on fuel or am I being led by the literature again?

 

[Deleted member 105431]

I hadn't heard of the makes Rinnai or Viessman before, are they as good as Vaillant or Baxi?

I looked up the 222f and it sounds impressive, I also saw the Viessman Vitodens 343-F which has integral solar cylinder and solar control unit. Don't know how much they are though, I couldn't find out on Google so far - are they rare?

On the Rinnai twinflow website it says that hot water storage tanks are expensive to run - does having a combi boiler save significantly on fuel or am I being led by the literature again?

rinnai and viessmann are comparable/better than vaillant for quality and alot better than baxi. combi's are cheaper to run for hw than storage systems but water usage can be higher if on a water meter.

glow worm ultrapower sxi 170 is a cheaper viessmann 222f but the rinnai twinflow is the rolls royce option.

 

[kirkgas]

I currently pay about £2k a year for gas and electric but the system is inefficient.

I can budget for any type of system but it needs to be planned for and budgeted before the floors come up and the tiles laid.

So far, I really get the hint from you all that gas is cheaper although the websites that are selling the electric UFH say it is equally as economical.
no surprise there is there!!
in a recent survey 1 out of every 7 dwarfs surveyed said they were happy.
it all depends who you ask which questions

 

[D_Hailsham]

in a recent survey 1 out of every 7 dwarfs surveyed said they were happy.

Only one dwarf happy? What were the other six cheesed off about?

At least it was a 100% sample , unlike the TV cosmetics ads which say that 95% of users are happy with the product, but in the small print at the bottom of the screen it says "87 users tested"

 

[electronicsuk]

The Heatmiser system from the earlier link looks fab but expensive, do you know what the average set up cost of a system like that would be?

Approximately £500 plus £100 per room would seem reasonable to cover the necessary fixed wiring, thermostats, wiring centres, valves and central control pad.

 

[Tweetie]

an wet UFH system on the ground floor would be the optimum, but it may be better if you fit radiators on the first floor

is that in case of leaks?

I like the idea of ufh downstairs with floor tiles and radiators upstairs, but I have a bedroom downstairs and the lounge is upstairs. Does the slow warm up times of wet underfloor heating mean it is more unsuitable for a bedroom since you only want it toasty to go to bed and to get up?

 

[Agile]

One of the major disadvantages of UFH which is rarely mentioned is that the slow heat up ( up to 3 hours ! ) is matched by a slow cool down.

Rads will usually allow a room to cool by 5-10° in 30-60 min.

Most people sleep far better in a cooler room but still need a comfortable temperature for undressing or lounging about.

Thats why I would always advise rads in a bedroom.

Tony

 

[Tweetie]

Design is certainly key and I appreciate all of your help.

Is it practical to have rads in each room plus a wet UFH just along the main walkway from the bed to the bathroom, just to warm up the tiled floor for bare feet?

 

[electronicsuk]

Is it practical to have rads in each room plus a wet UFH just along the main walkway from the bed to the bathroom, just to warm up the tiled floor for bare feet?

As you know, it's fine to mix rads and UFH on one system through the use of a blending valve, UFH manifold and pump, so this is no different. As long as you have independent control over the timing of the UFH and radiators, you will be able to set the 'on' time well in advance of getting up, in order to let the floor reach your set temperature.

 

[Tweetie]

I suppose the only drawback in making just a walkway of wet ufh is that the whole floor will need to be raised higher to accommodate the pipes.