Combi-Condenser Boiler Driving Few Rads.

[MarkFish]

I'm having a Condenser boiler fitted. [1]

The guy fitting, who seems pretty switched on, has made the point that the total output of the radiators is 3kw wheras the boiler will run far better with a total of 8kw of Rads in the system.

The suggestion is that we simply add more rads to take the total system up to 8kw. Actually this isn't a major problem - I planned to leave half the house totally without rads so I can just put rads in the rooms that I planned not to thus taking the total Rads up to 8kw.

HOWEVER, the reason I only want a handful of Rads in the system is that 1/2 the house is effectively heated by other means. So even if I put Rads with Thermostatic valves in the rooms with no Rads currently then 60pc of the Rads won't be putting out any heat most of the time anyway.

So how will adding more rads to the system help, if the exra rads are typically never on?

Surely it's possible to have a combi boiler that can drive 2-3 Rads but still has the umph to output plenty of hot water?

TIA.

[1] I should point out that the information in this post is the result of a garbled second hand message, so I could be misrepresenting what I've actually been told. None the less, I'd appreciate some understanding of the issues from DIYNot-ers before I talk to the chap.

 

[Boilerman2]

Most Combi's will modulate down to around the 5Kw mark, so your boiler may hunt a bit, but if it's only got a 3Kw load connected to it, it should not do it any harm fitting an "openTherm" controller may help provided your boiler is compatible with Opentherm protocol i.e Remeha, Keston etc

 

[MarkFish]

Most Combi's will modulate down to around the 5Kw mark, so your boiler may hunt a bit, but if it's only got a 3Kw load connected to it, it should not do it any harm

So maybe not a problem worth solving? We can just stick the 3kw load on it?

fitting an "openTherm" controller may help provided your boiler is compatible with Opentherm protocol i.e Remeha, Keston etc

Thanks, will investigate.




The more I think about this the more I'm questioning if I even want central heating. Maybe all I need is a hot watrer boiler. A fan heater with thermostat on a timer in every room for the 4 months of winter will keep each room at the temperature I want & I free up the wall space. I save a load of the cost of installation. The only maintainance I'd ever need to do is to go to Argos and buy another £25 fan heater when they break. Then in summer I can put all the heaters in the loft and have an uncluttered house.

The downsides is that I imagine selling a house with no central heating would be tricky & my electricity bill would be high. (Just out of interest can anyone tell me roughly what the price of electricity is relative to gas per joule or whatever they measure it in?)

Any views?

 

[MarkFish]

Most Combi's will modulate down to around the 5Kw mark, so your boiler may hunt a bit, but if it's only got a 3Kw load connected to it, it should not do it any harm

So could someone spell out to me the problems of running a combi with too little load?