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Rick Ridley
Rick Ridley, UK Heating Engineer
Category: UK Plumbing
Satisfied Customers: 1561
Experience:  30 Years on the tools, now retired, Ex CORGI
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We have a British Gas 330+ condensing boiler. WE have recently

Customer Question

We have a British Gas 330+ condensing boiler. WE have recently had underfloor heating installed which can be operated as a seperate zone. The boiler appears to function properly when heat is called for by DHW or Central heating. If underfloor circuit is run by itself all is ok for about 20mins then boiler cuts out with error code F25. This is max temp rise slope. Can you explain please
Submitted: 2 years ago.
Category: UK Plumbing
Expert:  Brian replied 2 years ago.
This is due a lack of circulation you will need to check that both pumps are working that is the central heating pump, and the circulator pump for the underfloor heating.