Energy options

Netexporter

Brie said:

If you have the heating ducts there then an air to air heat pump might be the best option.  

Heat pumps: how they work and types explained - Which?

Not the "normal"/cheap type, with an indoor and outdoor unit linked by a refrigerant pipe.

MP1995 said:

Does the boiler upgrade scheme apply to air to air heat pumps?

No, because they are classed as air-conditioners.

habahero

I will look into these, I suspect there would not be room however. Octopus's online quote thing with the BUS grant applied said it would cost £2,408 which is roughly what I imagine the other two options would be give or take (either electric rads, or small gas combi). It said it needs clearance around the outside unit of a meter each side and to the front, and also the cylinder inside is 2m x 1m, which could be interesting to locate somewhere - I imagine it may be the outside unit that caused issue though as it only has very small gardens and walls and I don't think I would have the clearance for it. Does anyone have any ideas as to the running costs of these vs the other two options?

If these are not viable, I'm still unsure as to which would be the better method either the GCH or the elec rads overall.

Spoonie_Turtle

habahero said:

I will look into these, I suspect there would not be room however. Octopus's online quote thing with the BUS grant applied said it would cost £2,408 which is roughly what I imagine the other two options would be give or take (either electric rads, or small gas combi). It said it needs clearance around the outside unit of a meter each side and to the front, and also the cylinder inside is 2m x 1m, which could be interesting to locate somewhere - I imagine it may be the outside unit that caused issue though as it only has very small gardens and walls and I don't think I would have the clearance for it. Does anyone have any ideas as to the running costs of these vs the other two options?

If these are not viable, I'm still unsure as to which would be the better method either the GCH or the elec rads overall.

Gas, definitely.  (There's a reason storage heaters were invented to be hated up at a lower overnight rate!) 
Currently the price of electricity is 4x that of gas per kWh.  With efficiency taken into account it's still at minimum 3x the cost of gas.  There are organisations pushing to try to change that, bring down the comparative price of electricity, but any progress looks like it's going to take a long time.

ASHPs are supposed to be able to run at around 300% efficiency on average, bringing the cost of running them roughly in line with gas.  In reality the efficiency depends on how well it's installed and the settings it's run at. 
People can get higher efficiency with some effort to find the optimal settings for their home, but on the other hand a lot of people get lower efficiency because the installations are suboptimal and/or they don't know how or aren't able to spend the time and effort learning about the system to find the best settings.

^ I mainly wrote that for context why they're seen as a step forward despite electricity being so much more expensive than gas, but turns out it is relevant to a question you asked anyway.

ka7e

I would second the recommendation for solar panels if your roof is aligned correctly, you would get a return on the investment in less than 10 years and probably future proof on rising costs for the next 20 years or so. Octopus do a special tariff for those with ASHP, with 3 cheap-rate periods a day (though peak rates are high!)

edwardrw

We had a Johnson and Starley boiler/warm air sytem, that broke. We eventually fitted a Vaillant gas boiler powering a J & S Aquair unit. 
There is nothing on their website saying that they have developed a low water temperature Aquair unit, suitable for the warm air system.