Replace analog timer?

[ericmark]

My immersion heater has a thermostat, so when water to temperature it turns off, OK my immersion heater also controlled by an iboost+ which means it only runs when we have excess solar power, and it can use just a 100 watt so run time means nothing, however the iboost+ also tells me how much it has used per day, last 7 days and last 28 days so easy for me to work out what it uses. So at your electric price, 31p per day if you use the same as me.

My oil boiler does not modulate, so did not need to measure oil used, it is 20 kW output and by experiment found it needed to run once a day, for ½ hour, well it did not run for ½ hour, after 20 minutes it started to cycle, and would not turn on again before ½ hour had elapsed. So total 6.6 kWh per day, likely more as not taking into account boilers losses. So 25/6.666*1.237 = 4.64p so gas would need to be less than 4.64p to work out cheaper than electric.

I assume your gas meter is actually calibrated in kWh, so this time of year no central heating, so turn to gas only, and run for 24 hour, and see how it compares. I would be interested to see results.

With my house, that wasted energy from oil will heat the house, in winter not a problem want the house heating, in summer, I have to consider how long the AC needs to run to remove that heat.

I would be interested in your results, in how much gas used in 24 hours when only heating DHW.

 

[Welshgasman]

No, the gas meter is just units. I have to apply the factor to get the KWh.
I would expect even I have a thermostat buried in the hotwater tank, so that reading was whilst it was heating the water to whatever temperature it does.
I will try and get readings for the gas when I put it back on for DHW. Experimenting at the moment.

 

[ericmark]

Thank you, please give us the results. There has been a debate for some time gas - electric, problem is with gas there is always waste, and no clear answer, using logic there must be as water use increases, a neutral point where both cost the same, low use electric wins, high use gas wins.

But it had been drummed into me for so many years that gas was cheaper, I just accepted it without question.

But when I realised my Nest Gen 3 thermostat was rubbish where installed, and I wanted a system which would continue to work with a power cut, to power Nest from a USB outlet was out, as it would not work with a power cut.

So I moved to Drayton Wiser, but by that time realised cheaper to heat DHW with electric so just got a central heating only hub for the Wiser, it has transformed my heating, main house now three points where if too cold, it can fire the boiler.