Heat pumps: avoid common woes
On cold nights, many people will rely on heat pumps to keep their homes comfortably warm.
When they work as they should, heat pump air conditioning systems are a convenient, efficient source of thermostatically controlled heating.
Yet, sometimes, just when you need them most, heat pumps can fail. Here’s just some of the ways things can go wrong.
Heat pump won’t respond
It’s freezing outside and you want to increase the heat inside, but nothing happens when you tap the temp-up arrow on your heat pump remote. The heat pump is working, but it’s like it’s not listening.
This all-too-common scenario can rapidly induce feelings of panic, but don’t worry; chances are your unit has not just failed catastrophically and the fix may be simple.
If your heat pump isn’t doing what you want it to do, or if you notice the display on your remote getting fainter and fainter, the first thing to do is change the batteries [usually two triple As].
If the batteries are going flat, the remote may not be able to send a signal to the heat pump.
Believe it or not, this is the most common problem heat pump experts come across.
To avoid panic midwinter, consider changing the batteries on your remote at least once a year.
Another suggestion is not to keep pushing buttons at random if you think your heat pump is not responding as it should. That will likely result in it going into default mode; just push the button once and give the unit time to respond.
The best thing is put it in heat mode with the fan on auto and set it to the temperature you want, then leave it alone.
Pump only blows cold air
Familiar for many will be the experience of getting up on a freezing cold morning, only to discover the heat pump is blowing out cold air.
Frosty mornings can be a little like kryptonite for heat pumps. As the temperature drops, it gets more difficult for the exterior units to extract heat from the outside air and eventually they simply freeze up. The flow of warm air will then stop for several minutes while the unit defrosts itself. This also explains why water sometimes can be seen coming from the bottom of outside units on a cold morning; it’s part of the defrosting process.
A 2017 appliance reliability survey conducted by Consumer found 8 per cent of members had reported heat pumps not performing adequately on frosty mornings. Heat pumps designed to heat down to -15°C will perform better in these conditions; the system should also be correctly sized for the room.
Sometimes leaves can build up behind the exterior unit, making it more prone to icing up. It’s definitely worth taking a few minutes to check that the outside unit is clear. Ideally, there should also be at least a metre gap between the front of the exterior unit and vegetation.
Dirty filters in the heat pump inside your home can also lower heating efficiency by blocking airflow to the coil that heats the air. Clean filters regularly with a duster, soft brush or a sponge and warm water and detergent.
Heat pump stops running
Some people prefer to run their heat pumps constantly, rather than switching them on and off. Yet, every now and then, they stop running for no obvious reason, perhaps because of a power surge or a slight thermostat fault. The best option here is to turn off the isolator switch by the outside unit, wait a few minutes and then turn it back on. This will re-set the unit and generally rectify the problem.
Professionals recommend having your heat pump checked and serviced to keep it in the best possible condition.