Contents


Basic central heating pump checks

My central heating pump is running, but it’s not pumping water around the system

My central heating pump is blocked full of dirt and debris

My central heating pump is noisy

My central heating pump is leaking

My central heating pump has no power

My Central Heating Pump is Not Adding Pressure to My Central Heating System

My Central Heating Pump is Too Hot

My Central Heating Pump is Only Heating Some of the Radiators

My Central Heating Pump is Constantly Turning Itself On and Off

My Central Heating Pump is Not Making Any Noise


Introduction

Central heating problems are often due, not to the boiler itself, but, to peripheral components such as central heating pumps and motorised diverter valves.

These parts are among the few moving components in the system and so are more likely to be subject to wear and failure over time.

But how do you know that it’s actually the central heating pump that has failed? What are the most common central heating pump problems? And, what are the key differences between a central heating system failure and a central heating pump failure?

In this guide we’re going to help you identify if it’s the central heating pump that is causing the problem, and then hopefully provide you with a solution to the issue.

Basic Central Heating Pump Checks

Before you panic, call a plumber and buy a brand new central heating pump, we advise performing a few basic checks. More often than not, central heating pump issues are down to a tripped wire. So, if your pump isn’t working, check the below.

- Check that the power to the pump is turned on

- Check that the power supplying the pump has not tripped out

- Try resetting the pump by switching off the power for a few seconds

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My central heating pump is running, but it’s not pumping water around the system

One of the most complained about central heating pump problems is: how the pump is running, but it’s not actually pumping water around the system. This is a complicated matter that could be caused by several issues. The most likely is that the propeller on the pump is stuck. This could be due to debris blocking the propeller, or it could be that one of the propellers is actually damaged.

Solution:

If debris is blocking the propeller then you will need to get your hands dirty and actually work on removing the blockage. If the propeller is damaged then you will unfortunately need to purchase a new pump.

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My central heating pump is blocked full of dirt and debris

Another complaint we often hear is how the pump is full of dirt and debris. This is due to the ageing central heating system. As the pipes and radiators get older they can start to break down and rust. This can build up within the pump and eventually inhibit the pump’s ability to move water efficiently.

Solution:

Again, if debris is impacting on the performance of the central heating pump then you will need to get your hands dirty and actually work on removing the blockage. You could also contact a plumber to conduct a chemical or power flush on the system. This would certainly clear the blockage, but please keep in mind that the latter could weaken joints and components.  

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My central heating pump is noisy

A central heating pump in full working order will have a slight hum and a minor vibration. If your pump is making excessive noise then it’s a clear sign that something is not working correctly.

The most common reason for excess pump noise is airlocks. This is where air gets into the pump and stops the water flowing smoothly.

Solution:

Most central heating pumps, especially those supplied by quality pump manufacturers like lowara and Grundfos, will come fitted with a bleed screw. This is a small component that can be used to remove air from the system. It is our firm advice that you follow the manufacturer's instructions when carrying out this task.

If you need help identifying the central heating pump bleed screw, then use the diagram we have designed below.

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My central heating pump is leaking

It’s a pretty obvious one, but if your pump is leaking then you have a serious problem. Leaking could be due to incorrect installation, the pump over vibrating (causing bolts to break loose), or it could even be that the pump has blown a seal to overpressure.

Solution:

If the pump has come loose then tightening all the bolts should fix the issue. If the leak is a more severe issue and is caused by something like a blown seal, then you will probably need to contact your pump provider. Most pumps will come with either a 2 or 5 year warranty.

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My central heating pump has no power

One of the more severe central heating pump complaints is a pump with no power. If the rest of the system (and your home) has power, then this is likely down to damaged or loose wires. Occasionally, on cheaper pumps, small leaks occur as the pump ages. If the leak gets to the wiring of the central heating pump then the pump will shut down.  

Solution:

Unfortunately, even if you manage to fix the damaged wires, it is unlikely that you will be able to fix the small leaks in the system. This means that you will have a continuous battle trying to keep the pump alive. Try contacting your pump provider in the first instance, as most pumps will be sold with a 2 or 5 year warranty (depending on the manufacturer).

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My Central Heating Pump is Not Adding Pressure to My Central Heating System

If the central heating pump stops adding pressure to your central heating system then it’s a good sign that something is wrong. Make these checks below:

Airlocks

As mentioned above, airlocks will stop water from flowing around your system smoothly. This will inhibit the performance of your pump and it could also become quite noisy. To fix this issue you will need to bleed the air out of the system. Please carefully read the manufacturer’s instructions before performing this task.

Frozen Pipes

If the weather has suddenly turned and the temperature drops a few degrees below zero, then there is a chance your pipes could be frozen. This often happens when the system doesn’t get used when people are away over the Christmas period. Remember, stopping pipes from freezing is easier than thawing out pipes. If the pipes are frozen then you will need to get space heaters, oil heaters and hair-dryers to thaw out the system.

Solution:

If you have tried both of the solutions above then it is probably time to call a plumber. In higher end pumps, the pump can actually detect when there is something wrong with the system and shut itself down. Again, it could also be due to smaller leaks occurring inside the pump. If you need to replace the system, check with the pump provider as you could be entitled to a free replacement under a 2 or 5 year warranty.

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My Central Heating Pump is Too Hot

The majority of central heating pumps will be warm to the touch. They are, after all, highly engineered tools shifting vast amounts of water at high speed. But, if the pump is getting hot to the point that it is difficult to touch, then it is clear that something is wrong.

Solution:

Unfortunately, if the pump is too hot to handle, then it is a sign of ageing and you will probably need to replace the pump. If the pump was bought within the last few years then you will probably be able to get a replacement from the pump provider under a warranty. Here at Anchor Pumps we offer 2, 3 or 5 year warranty depending on the pump manufacturer.

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My Central Heating Pump is Only Heating Some of the Radiators

If the hot water is only reaching some of the radiators in the system, then it’s likely that your pump pressure setting is set too low. There is also a chance that it could be debris in the system that is slowing down the flow of the water.

Solution:

First, try adjusting the pump pressure dial. This is a small dial fitted on most high quality pumps that will allow you to adjust the pressure in your system. Remember to add pressure to the system slowly. A sudden jolt could damage or weaken joints in your system.

If this doesn’t improve flow in the system then you may need to contact a plumber to flush the system. This should help remove and break up debris.

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My Central Heating Pump is Constantly Turning Itself On and Off

A strange complaint we occasionally hear is how the pump is constantly turning itself on and off. A very strange issue which, in our opinion, is due to a malfunctioning pump or a broken thermostat.

Solution:

The first check is to ensure the thermostat is operating correctly. Occasionally a dial can break, causing the pump to constantly start up and then shut itself down. If you have checked the thermostat and it is in full working order, then it’s likely that the pump is malfunctioning. Contact your pump provider, as you will likely be owed a free replacement under warranty.

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My Central Heating Pump is Not Making Any Noise

If your central heating pump is not making any noise and appears to be dead, then you may have an electrical issue. This could be due to a tripped RCD, a blown fuse or even a loose wire.

Solution:

Firstly, check that the RCD has not tripped. The RCD is usually located near the electricity meter or hidden away in an airing cupboard. If the RCD seems to be in full working order then you will need to check that the pump has not blown a fuse.

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