Heat Pump

 We had a fairly new gas hot water service in this house when we moved here 19 months ago. I don't know when it was installed, the agent said fairly recently, I guessed that could mean anything from 2 years to 8 years. The previous owners had been here 8 years and had done some renovations.

The fuel was bottled gas, piped gas not being in our street, but is a couple of streets away. I paid for two bottles when we moved in, otherwise we'd have no hot water. Having two bottles meant that when one emptied, you switched to the other bottle and ordered a new one. The new bottle was delivered in a few days, so there was a full bottle in reserve. Cost was $106 per bottle. A bottle was supposed to last for 10-12 weeks I was told, and that was the case for us for nearly all the first year, towards the end of which the price went to $116 per bottle. It quickly went to $137 for the next purchase. I wasn't greatly concerned at the price rise; we'd been softened up by all the talk about the war in the Ukraine and gas shortages in Australia due to political mismanagement of resources and bad contracts with gas companies.

What did worry me was that the last few bottles were only lasting 5-6 weeks. This was mid- winter. Could it be that the water going into device was so much colder and needed more gas to heat? Unlikely I thought. Could it be that we were using more water? Unlikely, we each bathed once a day, and had the same habit since we moved in. There was no gas appliance of any other type, just the hot water. Could it be that there was a leak in the unit, the connections, the pipeline. Possible. Could it be that they were not putting as much gas in the bottles? Possible I thought. 

After buying 3 bottles in quick succession, I rang a company that deals in electric heat pumps for some info. They sent me some options and quotes after they asked for and I sent photos of the existing HWS and meter box. We chose the more expensive of the three, an Istore 270 litre capacity which is popular because of its quietness of operation. It was installed within a week of making the choice. The cost of $3100 (with state and fed government rebates), should be recouped in a few years as it runs on the solar power during daytime. It gives us ample hot water for our evening baths and showers, hotter than the gas one we had. The water is still warm in the morning, but the unit has a complicated setting system of timers and modes and can be adjusted to whatever. Frankly I haven't mastered it yet, haven't needed to, but this morning I did manage to turn on the booster early to get hot water before the thing turns itself on at 10am. Rob is here staying with us and likes to shower in the morning.

Apparently heat pumps are an energy efficient way of heating water, and the energy going into that hot water is better than being paid a miserly 5cents a kw for our excess solar electricity produced. I'm happy not having to buy gas bottles, except the little one for the barbie.