Does my heat pump need servicing?

This is a bit of a grey area!

It depends on what you call a “service”. If you’re expecting an oil change and consumable parts to be swapped over, you’re going to be disappointed!

Put simply, there’s next to nothing in the way of “serviceable” parts in most swimming pool heat pumps – indeed most air source heat pumps in general. The part of any heat pump that does the hard work is its refrigeration circuit, which is a sealed loop. If this goes wrong, which is thankfully rare, it needs specialist attention. It’s not something that is otherwise touched.

That said, you do have to keep an eye on your heat pump, purely because there are a few factors that can affect its performance and longevity. Perhaps it’s fairer to say that your heat pump needs an annual check, rather than a service. You can get this done when your pool is opened or shut down for the season.

What needs to be checked?

Firstly, keep it clean. I’ve never met a machine that works better when it’s dirty. 
It makes a difference with heat pumps though, because the big radiator that wraps around its outside (the evaporator) is what captures heat energy from the air. It can’t do its job if the fins in this radiator are clogged up with cobwebs, leaves or dirt.

Don’t jet wash the unit though! These fins are only soft aluminium and are really easily bent. 

Which brings me to the next point…

Check the fins!

Bent, dented fins can affect a unit’s performance. Recently, I had a unit here in our workshop – the complaint was that the unit didn’t get the customer’s pool up to temperature. On closer examination I found that one entire side of the evaporator – a third of its area – was flattened. The unit was sucking in one-third less energy than it needed. No wonder it didn’t heat! Your engineer can put this right by using a fin comb. A few dents and dings is no big deal – but a significant area needs to be fixed.

Make sure your unit has all its screws in the right places, and the panels all fit neatly.

I’ve seen a few units where, after repairs have been done or the unit has been moved, the panels haven’t been refitted properly. Screws have been missed out and this can lead to unwelcome water ingress where there shouldn’t be any. Not to mention rodents (yes, it happens!).

Keep vegetation pruned back.

Encroaching shrubs and trees can affect airflow, which can in turn lead to performance problems and even frosting. 

Check the sensor readings

Just to be assured that the unit is working well, check your sensor readings – there’s a separate article on how to do this and what they mean.

Overwinter the unit properly. Don’t leave water in the heat exchanger – it can freeze, the heat exchanger splits, and then when you reopen the pool you’ll have a very expensive repair.
When reopening the pool…

Give the heat pump fan a spin before you turn the power on, just in case it’s a bit stiff from sitting there over winter (hey, it happens to the best of us). When the unit is up and running, switch it into cool mode just to check the defrost function works properly (if your model has this feature).