What causes heating on but no hot water?

Faulty diverter valve stuck in heating-only position. Broken mid-position valve. Hot water cylinder thermostat set too low or failed.

How much does it cost to fix heating on but no hot water?

Typical costs range from £928 to £2,726 depending on severity and location. Get a free quote from a local heating engineer on Tradesfolk.

Fix SoonCommon in SepRecommended trade: Heating Engineer

Heating On but No Hot Water

Central heating radiators work normally but the hot water taps run cold.

What Is Causing This?

1Faulty diverter valve stuck in heating-only position
2Broken mid-position valve
3Hot water cylinder thermostat set too low or failed

How Urgent Is This?

Fix Soon

This should be fixed in the coming weeks. Leaving it may allow the problem to worsen and cost more to repair.

What Needs to Be Done

A heating engineer will test the diverter or mid-position valve, check the cylinder thermostat, and replace the faulty component to restore hot water.

How Much Will It Cost?

£928 – £2,726

National average estimate

Labour: £565 – £1,488 | Materials: £363 – £1,238

Enter your postcode for a local price estimate

Prices are estimates based on typical UK rates. Actual costs depend on the specific issue, accessibility, and your location. All quotes from tradespeople on Tradesfolk are completely free.

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How to Prevent This

Have the diverter valve checked during annual boiler servicing. Set the cylinder thermostat to 60 degrees. Avoid switching the system on and off frequently.