Common Signs of a Faulty Heating Pump

If your radiators are staying cold — or you’re getting hot water but no heating — your circulation pump could be on the way out.

At EPM, we’ve replaced more than a few heating pumps across Exeter. Sometimes they fail completely, other times they just lose performance gradually.
Either way, if you know what to look for, you can avoid a freezing home come winter.

What Does the Pump Actually Do?

Your heating pump (also called a circulation pump) is responsible for pushing hot water from your boiler around your radiators and back again.

If it’s struggling or stuck, you might have:

• Hot water but cold rads

• Some radiators heating, others not

• A boiler that keeps shutting down

5 Signs Your Heating Pump Might Be Failing

1. Some Radiators Stay Cold

Especially those furthest from the boiler. This is often due to poor water flow — a pump on its last legs may not have the strength to circulate fully.

2. The Pump Is Making Strange Noises

Whirring, grinding, humming or rattling noises usually mean worn bearings or air in the pump. If it’s loud, it’s not happy.

3. Heating Takes Ages to Warm Up

If your system takes forever to get going — or the radiators never feel as hot as they used to — it could be a sign the pump’s losing pressure.

4. The Pump Is Hot to the Touch

Some warmth is normal. But if it’s getting seriously hot (or causing the boiler to overheat), it might be seizing up internally.

5. Boiler Lockouts or Error Codes

Modern boilers will shut down or show a fault if the pump isn’t circulating water properly. We’ve seen this one catch people out after a recent power cut or drain-down.

What Causes Pump Failure?

• Age (most last 10–15 years)

• System sludge or debris

• Dry running after an airlock

• Electrical faults or poor wiring

• Incorrect speed settings or wrong pump size

Can It Be Fixed?

Sometimes. We can try:

• Bleeding the pump to release trapped air

• Adjusting the speed setting

• Cleaning it out if it’s blocked with sludge

But if the motor or bearings are gone, replacement is usually the smarter call. Pumps aren’t wildly expensive, and it’s often cheaper to fit a new one than limp along with patchy heating.

How Much Does It Cost?

For a typical home heating pump:

• Supply and fit: £250–£400 depending on the system and access

• Premium models (like Grundfos Alpha with smart features) may cost more, but improve performance and efficiency

We always quote up front and only replace if we’re sure it’s necessary.

Final Word from EPM

If your heating feels like it’s giving up — and the boiler’s working fine — don’t forget the pump.
It’s one of those parts that often gets ignored… until the house goes cold.

Want us to take a look? We’ll check it, test the flow, and give you honest advice — no pressure, no guesswork.