myson apollo 30/50s

[ericw]

Boiler works until casing gets hot, then works for 30 secs every 5 mins. If airtight case is removed, boiler works perfectly. Flue is OK and fan is running.

[ALDA]

DONT BE FOOLED INTO THINKING THAT THE CASE IS THE PROBLEM!
WITH THE CASING REMOVED, THE HEAT FROM THE BURNER IS DISSIPATING BEFORE ITS HAD A CHANCE TO HEAT THE WATER!

CHECK FOR.
SLUDGED UP SYSTEM MAYBE!
COULD BE GAS TO WATER HEAT EXCHANGER IS CLOGGED!
FAULTY PUMP!
BYPASS VALVE MAY BE TOO CLOSED!

[Oliver_murphy]

Check the seal around the inside of where the casing fits, it wil be broken somewhere, and needs replacing.