Rinnai INFINITY® Compact Controller (MC912A)


Discontinued Jul 2018. Superseded by the Compact Controller MC601A.

Smallest most affordable model. This controller can be installed anywhere in the house.

Digital controllers allow you to select the exact temperature of the hot water at the tap within the controller temperature range.

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Product Details

Benefits of a controller:

  • Safety, especially if you have young children, the hot water can be preset to a child-safe level

  • No need to mix hot and cold water, this reduces the effect of temperature spiking when another tap in the building is turned on

  • You use your continuous flow unit more efficiently as less gas is required to heat water to 40 °C (typical shower temperature) than at 55 °C (default temperature without controllers)

  • Allow diagnosis of problems (such as gas supply disruption) in the unlikely event or a fault, or for a maintenance review when the INFINITY is serviced.

Extended warranty
Rinnai INFINITY installations, when a controller is installed receive an extra two years on the INFINITY warranty.

Technical Specifications


Off white with a grey touch pad

Comes with

All controllers come with 10 m of cable.

Available temperature settings

37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 48, 50, 55 °C (60, 65 °C HD models)

Rinnai product code


INFINITY model and controller compatibility

Current range of INFINITY water heaters and controllers:
- A-Series, HD-Series, and EF26
- Deluxe bathroom (MC-100V) and Deluxe kitchen (MC-BC-100V) controllers

Discontinued range of INFINITY water heaters and controllers:
- EF250, EFi250, VT-Range, XR-Range
- Wireless controllers (MC502S, MC503S)


IP rating

Rinnai controllers are not IP rated. The controllers are low voltage (12 V DC) from the Rinnai INFINITY via a cable to the controller. Rinnai does not recommend placing a controller where they will get wet from a shower head, tap or water fixture. They are water resistant, not water proof.


July 2018

Suitable for these products

Installations with a Rinnai INFINITY continuous flow gas hot water heater installed, refer compatible water heater models in the 'Tech Specs' section. Each remote controller can be individually programmed, however the water heater can only deliver one set temperature at any time.

Rinnai water controllers cannot be used with Rinnai INFINITY units connected to solar systems, when a Rinnai iHeat is installed, or in a ring main system using N-Series models.

Controllers are water resistant, however, durability is improved when positioned outside the shower recess. All deluxe water controllers must be installed at least 400 mm above the highest part of a sink, basin, or bath.

Controller configurations
A maximum of four water controllers (three for the N-Series) can be fitted. Any combination of the deluxe, compact, and wireless* controllers can be used within the following parameters:

• Only ONE master can be installed. This can be a Kitchen Deluxe, Compact, or Wireless* Controller.
• Up to two Bathroom Deluxe Controllers can be installed.
• Fourth controller in any installation must be a Compact or Wireless* Controller. 

* The wireless controller is discontinued