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Samsung Gen6 12KW heat pump and pasteurisation cycle - only uses the booster
Hi,
I have a Samsung Gen 6 EHS 12KW heatpump with a wired remote controller that is also used as the primary thermostat. I have mastered most of the Field value options, correcting some major setup flaws such as the weather compensation flow temps being set by the UFH…..when I didn’t have UFH! I have fine tuned the radiator weather compensation and the controller is very flexible in setting the minimum flow and rate of change vs ambient.
However, I noticed my electric bills on the day set to pasteurise the 210 litre DHW cylinder was eye watering on some weeks. Then I noticed that if the tank temp happened to be at the lower end (just before the heat pump reheated), sometimes 40C, when the schedule for pasteurisation started, the DHW tank was only heated using the 3KW booster immersion. And boy did that use a lot of electricity to heat it up to 65C.
Does anyone know how to get the heat pump to raise the hot water to its max temp (I have found this to be about 53C, and then let the booster take over? Why doesn’t the pasteurisation cycle activate the heatpump?
Posted by: @peterrsaltingsDoes anyone know how to get the heat pump to raise the hot water to its max temp (I have found this to be about 53C, and then let the booster take over? Why doesn’t the pasteurisation cycle activate the heatpump?
That’ll almost certainly be a controller thing. Our system is the same. If the legionnaires cycle is due, it kicks over to the immersion immediately on schedule and doesn’t care what the tank temperature is. It just does it’s thing till it gets to 65C.
What you could do, if you have a smart metre on tou tariff is to do your legionnaires cycle in the early hours.
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Posted by: @peterrsaltingsDoes anyone know how to get the heat pump to raise the hot water to its max temp (I have found this to be about 53C, and then let the booster take over? Why doesn’t the pasteurisation cycle activate the heatpump?
you can schedule your hot water to be heated by the heat pump and also schedule your legionnaires cycle. If you schedule the heat pump to heat your water to 53°C, shortly before the legionnaires cycle, then this will minimise the cost.
@mike-h but that won't be automated will it? That would have be done manually, which requires a lot of reminders.
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@peterrsaltings not quite sure why you @'d me into here, I don't run legionella via my controller at all. I heat the whole tank to 55C every day with the heatpump. I use the whole tank every day. it occasionally heats to 65 on a PV diverter but thats by the by.
My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs
Thanks for the suggestions. I schedule the pasteurisation cycle each Sunday. When my Octopus Cosy off peak tariff becomes available at 1pm, I manually crank up the DHW…..and the heat pump manages to get the hot water to 53.5C….wont go higher. Then the 3KW booster heater takes over at 2pm and usually gets to over 60C by 4pm. As you say Mars, a weekly reminder on the iPhone.
I use weekly timers to set different thermostat temperatures for the house heating during the day, to take advantage of the cosy tariff. But I cannot use a weekly timer for the DHW, just a daily one. Is that another limitation of the Samsung controller? Otherwise a weekly timer, set just for Sunday 1pm, with a 55C target temperature would have been ideal, but I don’t think the Samsung controller lets me do that for DHW.
PS the daily timer is also just on/off and mode (economic, standard, boost or forced). Cannot select a new temperature 🙁
Hi Ian, I saw you had a Samsung heatpump and you seemed very knowledgeable about getting the most out of it, so I tagged you. But seems your 16KW model can get to 60C (each day) so no need for the pasteurisation cycle. You must use a lot of water in your house! I used to, before I kicked out my 2 young adult kids, who would stand in the shower all day if they could. 🙂
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