Central heating pump not working

Image of a central heating pump

Troubleshooting guide for household central heating circulating pump

The circulation pump's role in your central heating system is vital. If something goes wrong with it, you can expect issues with your hot water and heating.

In this post, we'll describe what a circulating pump is and how to recognize issues. We'll then guide you through our circulation pump repair checklist.

What is a circulating pump?

A circulating pump is a water pump that circulates heated water in your heating system. The heated water passes from your boiler to the pipes that supply your radiators, towel rails, and hot water cylinder. The water then returns to the boiler to keep a constant supply of heated water flowing around your property.

The circulation pump is usually integrated with or near your boiler, or in an airing cupboard next to your hot water cylinder.

Central heating pump not working?

There are a number of warning signs that your circulator pump system is not operating effectively. You may detect the following indicators:

  • Despite the pump operating, the water flow pipe isn't hot.
  • A pump leak has occurred.
  • The pump is making peculiar noises.
  • The pump casing is hot.
  • Your radiators aren't heating up or are only partially heated.
  • No hot water is available to you.

The main causes of this are blockages or an airlock in the system that can be repaired. So, follow our step-by-step guide below to identify and repair any issues before replacing the pump.

Common problems and how to fix them

Follow our boiler circulating pump repair procedure below to learn how to fix the most frequent issues.

  • There's no water flow throughout the system.
  • The water pump makes a lot of noise
  • The pump was blocked.
  • The pump is leaking.
  • Incorrect pump speed settings
  • Loss of power
  • The pump will not turn off.
  • pump installed incorrectly

There's no water flow throughout the system

Your circulator pump may be stuck if it continues to run but doesn't move water throughout your system.

Give the pump a slight tap if it doesn't work. This may be all that is required to free up any components that have become stuck.

If this doesn't work, or if the pump gets stuck frequently, it's probably time to replace it before it breaks entirely.

The water pump makes a lot of noise

If your pump is making a lot of noise, there may be an airlock within it. Airlocks can cause your pump to fail, but fortunately, they're easy to fix.

Follow these steps to remove the airlock from a circulating pump that is outside of your boiler:

  1. Turn off the pump's electricity.
  2. On the pump, look for the tiny bleed screw.
  3. Place a cloth beneath the screw since the pump is still full of water.
  4. Allow any air to escape by turning the screw extremely slowly (a quarter turn or less is usually sufficient).
  5. Make sure the screw is adequately tightened.
  6. Turn the power back on.

If this does not work, there's a chance that the pump's bearing has come loose. If this is the case, you will have to replace the circulation pump.

The pump was blocked.

The circulating pump may be clogged or stopped functioning if your heating is taking too long to warm up, isn't reaching full temperature, or isn't working at all.

Blocked pumps can be caused by a build-up of sludge and metal particles in the heating system. The dirt might become trapped in key components, such as the circulating pump, causing them to fail.

Call in a Gas Safe Registered engineer to inspect the problem. To clean out the system, they may need to carry out a system cleanse or power flush.

The pump is leaking

If you detect water leaking from your circulating pump, it's most likely due to a loose or blown seal.

To begin, tighten up all of the connections with an adjustable spanner or wrench.

If it's still leaking, inspect all of the pump's connections. Corrosion on some components is possible. The pump will have to be replaced if this is the case.

Finally, examine the pump's joint for any leaks. If the seal on the pump has blown, this is where the leak is originating. In this case, contact a Gas Safe Registered engineer to either replace the seal or, if necessary, replace the whole pump.

Incorrect pump speed settings

Adjustable speed and flow settings are available on some pumps. The settings are commonly between 1 and 3, with 1 being the slowest and 3 being the fastest. If your radiators aren't hot, you may need to make adjustments to the speed and flow settings.

Loss of power

If your boiler is operational but your pump isn't, there may be an issue with the electrical wiring.

It's important to get the wiring checked by a heating engineer. They might be able to repair the wiring, or if the pump is old and rusted, it's probably more cost-effective to replace it with a new one.

pump installed incorrectly

The pump may be attached incorrectly if it's not working.

If you have an issue with your circulating pump, it's time to turn to the pros. Get in touch with a skilled heating engineer so they can assist you in diagnosing and fixing the problem as soon as possible.

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