Yes it probably is.
I contacted Worcester today about an issue with my boiler.(which I eventually fixed) When you ring their number there is a long message asking customers not to request an engineer for frozen condensation pipes. Basically the customer has to clear the frozen water/blockage themselves. In essence, every condensing boiler 'must' have a condensation pipe, so the water goes somewhere. That somewhere being outside the house.(drain, path, etc)
If I was you I would ring a boiler manufacturer, plumbing shop or plumber and ask either of them before using your boiler.
Don't be shy Manc Guy. http://www.worcester-bosch.co.uk/homeowner/customer-service/contact-centre As if.:lol:
