Detached property, hosted by Dave

We were replacing a 30 year old gravity fed hot water system powered by an oil boiler. 
 
We decided to go for an ASHP solution from Aira who provided us with a comprehensive all inclusive fixed price quote with a 15 year guarantee. At the detailed design stage they had to increase the number of radiators that had to be replaced but they still honoured the original price.
 
Prior to install we had to clear-out our garage and make some loft space (for access). We also had the old oil tank decommissioned and removed.
 
The install started promptly on a Monday morning at the start of April and finished that Friday afternoon (1 week x 4 engineers). We were fortunate in being able to keep hot water all week during the install (utilising the electric emersion heater in our old DHW tank).  
 
Our old radiators were swapped out for new ones but our old copper pipework was re-used (just adjusted above floor level for wider radiators). A small area of floor was lifted and later reinstated by Aira to connect the ASHP system into the existing pipework. The old header water tanks in the loft, hot water cylinder and oil boiler were all decommissioned, removed and disposed of by Aira.
 
Our system is now a pressurised one, providing fresh water to all cold taps and power shower strength hot water to the hot ones (although we are now having to replace the old en-suite shower as it cannot withstand the higher pressures).
 
We experienced a couple of very minor leak miss-haps during install but everything else went very smoothly. We found the whole install process a extremely positive experience. 

We have been left with a very neat and tidy modern heating system all controlled through a simple to use phone app.

It’s still early days for us but we are coming to terms with changing our mind set from running an aggressive reactive heating  system to a more subtle 24/7 proactive one.

 
We have only had a couple of coldish days in April but on those occasions the house felt nice and cosy. We will have to wait for next winter to fully prove how well it works.

 

Power wise we are continuing to use our existing Intelligent Octopus Go tariff as this is ideally suited for our electric car. We think (but are carefully monitoring) that this is going to be better overall than the tariffs solely designed for ASHPs. My basic calculations (using Aira’s energy analysis figures for our home) predict that we could spend £200 more pa on fuel than we did previously (noting we will now be heating the house 24/7),  but I am hoping all the built in over-cautious assumptions in the calculations will reduce the reality to nearer zero. In comparison replacing our system with a modern efficient oil boiler would potentially have saved us up to £200 pa to run, but may have cost us more to maintain and be far less eco-friendly (4.5 tonnes of CO2 pa). 

 

Investment wise we have spent a total of £7,135 (this includes oil tank disposal, government grant and VAT waiver) compared to a conservative estimate of £8,000 for a suitable replacement oil fired system for our property.