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Christopher buzzard

Gas Engineer
Jun 27, 2017
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Suffolk
Member Type
Heating Engineer (Has GSR)
Evening all. Asked by customer to look at new unvented installation he recently had done by others. Number off issues picked up on the install but the my main concern was the fact they converted the back boiler from open vented to a sealed system. Expansion vessel is way undersized. Am I right in thinking this conversion can't be done as the back boiler doesn't have an overheat stat if the thermostat fails.

Regards
 
Certainly should get vessel size sorted as could be constantly be
discharging if under sized.

Many back boilers can be upgraded from open vent to sealed system,
and some can run sealed without modification.

You should consult the manufactures instructions or contact the manufactures direct for confirmation. It may be that the necessary upgrade has been carried out (if required).

Boiler should be not be used if not permitted to be used sealed as could be dangerous.
 

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