Ground Source Heat Pump Problems

Things to Look Out For and What To Do If The Worst Happens

Ground source heat pump problems can be avoided if you have your system sized and installed by a reputable company that knows what it is doing. However, you might find yourself stuck with a poorly performing or malfunctioning system for any number of reasons. For example, you may have inherited the system from the previous owner, or perhaps you tried to cut corners yourself on the installation and are now regretting it.

Whatever the cause of the problems you are facing, rest assured that there is almost always a solution. This guide will help you troubleshoot the problems yourself initially and, if professional advice is required, tell you the right kinds of questions to ask of the technician who comes to investigate.

The Heat Pump System

Before we get into talking about the problems that can crop up, its worth spending a little time refreshing our minds about how a ground source heat pump works and the component parts that make up the whole.

A typical ground source heat pump system comprises the following parts.

• The Ground Loop (the bit where the heat is sourced)
• The “Heat Pump” itself – the mechanical heat engine part that serves as a fridge in reverse
• The Heat Sink – e.g. your underfloor heating coils

These are the main bits of the system that you would need to look at to fix any problems and it is useful to bear these pieces in mind as you read on.

If you are keen to go into more detail, you can find more in depth articles elsewhere on this site.

Do you need a professional?

Depending on your level of knowledge and technical competence, you might need to consult a professional at some stage. However there are some basic checks that even a complete lay person can easily carry out. Let’s start with those.

Customer-Led Troubleshooting

Before you reach for the phone, its a good idea to investigate the problem, if for no other reason than you will be better able to describe what has gone wrong to the technician so that he or she can be prepared when they visit you.

• Is the system plugged in and receiving power? Obvious I know but this can be overlooked quite easily. The potential embarrassment (and cost) when the engineer comes out, plugs the unit back in and then goes on his merry way having charged you a nice callout fee is worth avoiding.
• Visual check. You might be surprised as how much you can find out just by looking in the right places. If something looks wrong, the chances are that it is wrong! So, check for leaks, worn or broken cables and other signs that something is amiss with your system.
• Has your circuit breaker tripped? This is a very obvious thing to check and could save you having to go any further with your investigations. Just flick the switch on the breaker back into the “on” position and you’re back in business.
• Have you set your system thermostat correctly? It is possible that you, a small child or a pet has accidentally knocked the thermostat and caused it to set the operating temperature to something that you don’t want. I’ve also seen heat pumps put into reverse by mistake (cooling instead of heating), so this is also worth checking.
• Is water flowing through the heat exchanger? You can tell this by listening carefully or by touch.
• Does your air filter or the coils require a change? If they have become dirty, this can impede the flow and cause your system to malfunction. Give them a clean or change them for new ones.
• Is the pressure high enough in the loop system where the heat is absorbed or emitted?
• Are the pumps operating correctly? A failed loop pump will cause the entire system to fail.

Professional Advice

If you’ve checked all of the above issues, then it’s time to get a professional on site. Make sure you find a trusted service engineer (personal recommendations are often the best way to ensure that the quality of the technician’s work will be of a high standard).

Some of the issues that might require professional intervention include the following.

• Refrigerant problems. The refrigerant is the fluid that does all of the hard work inside your heat pump, so if there’s something wrong with that, it is likely to affect your system as a whole. Typical problems could include low refrigerant levels, scale or fouling of the heat exchanger or a problem with the reversing valve.
• Warm air not warm enough. A common cause of this problem is that the flowrate of the air through the system is too high. This means that the residence time of the air is too short and it doesn’t get heated up enough. This problem is normally easily fixed by reducing the speed of the fan.
• Generally reduced performance. Less than expected heating or cooling performance is often caused by reduced airflow and can be fixed by replacing the air filter.
• High humidity inside the building. This is sometimes caused by an excessively high air flowrate or by the heat pump unit being too big for the job. Adjusting the speed of the fan can often resolve this issue.

If you do find yourself having problems with your ground source heat pump system, don’t panic. A careful visual check can sometimes resolve the problem.

And if you keep your heat pump regularly serviced, it should last you a long time.

If problems persist, obtain the help of a professional. Don’t forget that most companies will guarantee their work for a period of time. Make sure you use a reputable company, preferably based on personal recommendations and you will be fine.