How the Water Heater Contactor (Switch) Works

How the Water Heater Contactor (Switch) Works


– Purpose of the water heater switch

– How the water heater contactor works

– The off-peak/peak option in your contract

What is a contactor? Contactor is a switch. Many electrical appliances consume a lot of electricity, including the electric water heater. By programming the operation of this electrical equipment during off-peak hours, the day/night contactor is one of the solutions that can reduce your bill.

Purpose of the water heater contactor


The electric water heater is undeniably one of those energy-consuming appliances. This modular device is an excellent tool for managing your home’s energy consumption. The day/night contactor connects your electric water heater to your home’s main electrical panel and allows you to switch to off-peak/peak hours.

However, to use this accessory, you must have a subscription with your energy supplier with an off-peak/peak option. The preferential tariff corresponds to a period when the energy demand is lower in the sector concerned.

Operation of the water heater contactor


To help you save money, the Day/Night Heater Switch will automatically turn on your water heater during the off-peak hours established by your subscription. It is an electromechanical water heater relay that opens or closes the electrical circuit according to the order received from the electricity distributor when the off-peak/peak switchover (Off-peak time/peak time.).

The water heater contactor has several functionalities to adapt to your needs:

– in Off-peak time/peak time. position, to benefit from off-peak operation at a preferential rate;

– in the forced position, to anticipate a high demand for hot water (when there are more people than usual on your roof), regardless of the time slot;

– in the off position, suspend the operation of your water heater for a significant period (e.g., during a prolonged absence).

Operating table of the day/night water heater switch

Off-peak hours

Peak hours

– The meter receives a signal from the supplier.

– The contact closes on the contactor coil.

– The coil closes the contact on the heater.

– The counter receives a signal.

– The contact opens, and the coil is no longer powered.

– The water heater stops working.

Some water heater contactors automatically switch back to Off-peak time/peak time. mode if you have forgotten to put your contactor in the forced position.

Attention: the supplier’s signal is received by your meter; however, the operation in Off-peak time/peak time. of your water heater will only be effective if the connection of your water heater contactor is correct.

The off-peak/peak hours option of your contract


You have just moved in or installed an electric water heater, and you would like to benefit from an off-peak/peak option to install a water heater contactor? Contact your supplier to change the options in your basic contract or take out an agreement with this option.

The table below compares a conventional contract with an Off-peak time/peak time contract.

 2 Types of hydro bill contract


Classic contract

Off-peak contract


– A fixed price per kWh throughout the year.
– The basic subscription is lower than for an off-peak/peak option.

– Variable price: the preferential off-peak rate is on average 40% lower than the basic kWh rate.
– The hours cover 8 hours per day and are generally between 11 pm. and 7 am., but they vary according to region.

Let me advise you of one good address if you are looking for HVAC accessories to help you make your home more comfortable. You will find a whole range of such products at Coretemp Heating and Air Inc. This is no-nonsense quality and value for money accessories and service beyond reproach.

Get yours and let us know of your experience!