Mitsubishi Ecodan-Zubadan in Hybrid /backup configuration with gas boiler

Air Source Heat Pumps (ASHPs)

Last Post by sorin 10 months ago

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sorin

(@sorin)

Active Member Member

Joined: 10 months ago

Posts: 4

Topic starter 09/12/2024 3:35 pm

Hello!

I own a Mitsubishi Ecodan / Zubadan ASHP 14kW with a gas boiler attached as backup heat source. It can help in colder periods but it should also switch based on energy price.

Mitsubishi also released this document

HOCTORREFRIGERATION.COM "https://hoctorrefrigeration.com/wp-content/uploads/2020/09/ECODAN-Hybrid-Boiler-Application.pdf"

Which states that it can be achieved but it is not technical.

The HP has an Intelligent operation mode where it can select Cost based between electricity and gas based on the price/kW of each energy.

I expect as example that at a certain outside temperature,

COP=3 and 3kW of heat are produced from 1kW electricity
1kWh electricity costs 0.6. But it produces 3kWh heat with a cost of 0.2 /kWh heat
1kWh produced with gas costs 0.2 => it produces 1kWh heat with a cost of 0.2
=> it should stay as it is for now. As soon as the outside temperature drops and COP drops => it should switch to gas boiler which becomes cheaper /kWh produced.

Settings:
Service menu / Operation settings / Boiler Operation / Hybrid settings/Priority Mode: Cost
Service menu / Operation settings / Boiler Operation / Intelligent settings/Energy Price / Electricity: 0.6 */kWh
Service menu / Operation settings / Boiler Operation / Intelligent settings/Energy Price / Boiler : 0.2 */kWh

I can force a boiler operation when accessing
Service menu / Heat source setting (Standard/Heater/Boiler/Hybrid *7) : Boiler.

But when i select Hybrid, it only runs on HP, although it should switch based on the Cost setting.

To test, I used a ridiculosly increase price for electricity (1000x) and it does not switch to gas.

I can also force only boiler operation using the settings:
Service menu / Operation settings / Boiler Operation / Hybrid settings /Outdoor ambient temperature: HP-Boiler when under -15 and Boiler to HP when over 1 (deg C). But it does not account the cost variable and it never switches.
The manuals say very little about this topic. They say it should work.

if anyone has this setup and can advice or is an installer that did this before. thank you in advance for helping me out.

This topic was modified 10 months ago by sorin

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