Openai/695d629f-dc6c-8008-bab0-faca20b4b3ee

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gpt-5-2

User: Does this daikin heat pump controller use this cost information to alter the heat pumps operation to maximise the benef…

Does this daikin heat pump controller use this cost information to alter the heat pumps operation to maximise the benefit of low tariff periods? If so how does it do it? If so how does that work with the weather compensation curve? If it does all this tariff optimisation, I assume I need to setup the weather compensation regardless of tariff stuff to begin with?

Assistant: Great question — and good photo, that helps.

Great question — and good photo, that helps.

Short answer: On most Daikin heat-pumps, those “High / Medium / Low” electricity prices do NOT automatically make the unit arbitrage the tariff (i.e. run harder in cheap periods and coast in expensive ones). They are mainly there so the controller can estimate running cost and, on some models, influence only a couple of specific features.

Below is the longer explanation.

1️⃣ What those tariff settings actually do (most Daikin models)

Depending on the exact controller/firmware, they are normally used for:

✔️ Cost estimation

Used for the “energy / cost history” screens so it can say:

“You used X kWh, approx £Y”

✔️ Hybrid/backup heater decisions (if fitted)

If you have:

• a hybrid gas boiler + heat pump, or
• a large electric backup heater

the controller can compare:

• electricity price vs
• gas price (if entered) vs
• efficiency (COP)

and decide:

➡️ “Use heat pump” or ➡️ “Use boiler / backup heater”.

But even here, it is not trying to time-shift for cheap periods — it’s only choosing the cheapest heat source at that moment.

2️⃣ When Daikin does optimize for cheap tariffs

Daikin only really does tariff-driven shifting if:

🔌 You have Smart-Grid / external tariff contacts connected

Some units have terminals labelled things like:

• SG1 / SG2
• Smart Grid
• Demand Response

These allow an external device (home battery, smart tariff controller, DNO signal, etc.) to tell the heat pump:

• Run normally
• Run eco / reduced
• Block
• Boost (store heat now) ← this is the only time it “pre-heats”

But this requires external control hardware. The internal “0.42 / 0.28 / 0.14” price settings alone don’t make this happen.

3️⃣ Interaction with weather compensation

Weather compensation remains the primary control strategy:

Outside colder → flow temperature rises

Outside milder → flow temperature falls

Tariff prices do not change the WC curve.

If Smart-Grid boost is used, the heat pump typically:

➡️ Shifts slightly up the WC curve temporarily (stores some extra heat in the house / buffer), then returns to normal after the cheap period.

But again — only if you’ve wired that feature in and configured it.

4️⃣ So — should you still set up weather compensation?

YES — absolutely.

Weather compensation is the foundation:

• best comfort
• lowest running cost
• longest compressor life

Think of the order like this:

1️⃣ Get weather compensation tuned first 2️⃣ Then (optional) add tariff-control / smart-grid if you have the hardware 3️⃣ Tariff price entry = mostly cosmetic unless hybrid or backup heater logic applies

5️⃣ Quick check — your setup

If you want, tell me:

1. Model of indoor and outdoor Daikin units (e.g. ERGA / EHBX etc.)
2. Whether you have: - hybrid boiler - immersion or electric backup heater - buffer or thermal store
3. Whether you have Smart Grid / demand response terminals wired

Then I can tell you exactly what those tariff settings do on your specific controller and whether there’s anything useful to configure.

Happy to walk through tuning your weather-comp curve too 👍