Going off the boil

Its been another quiet few months at Dung Heap Central. The broken fence posts have been spliced and concreted in place. The garden has awakened from its short winter slumber. Oooo how poetic. Things are just puttering along with no real work on the house to speak of an not much worth blogging about.

Murphy has a law  "What ever can go wrong, will". Well Murphy has been spending a lot of time at the Dung Heap over the past couple of weeks. The biggest issue has been our boiler. Unlike Most Canadian homes where the furnace and hot water tank are separate items, we have what is known as a combi-boiler. Simply put its a smallish gizmo that heats water for both a closed circuit for the radiators and for the hot water supply to the taps. Most of the bits in these are pretty much off limits to DIY and non-certified people so after it started making noises and the hot water supply started acting up we called in a professional.

Turns out the heat exchanger had cracked internally and the hot water was mixing with the closed heating circuit. The result was the pressure gauge going skyward and the hot water pressure went to a trickle. This lump is the main heat exchanger.

You can see by all the green oxidisation just how bad this thing has been leaking and for quite a while.

Well the nice man quoted £641 for the repair. Ouch!!! Checking on line the part is less than £200 so they were looking at over £440 just in labour. A brand new boiler would have been only £750 but again the labour quotes ranged from just over £1700 for a simple boiler & installation to a whopping £3300 for the full Monty with radiator power flush, etc, etc,etc.

Looking about on some DIY sites to see if it could be a self fix job, it seems that since the heat exchanger doesn't need the gas touched it doesn't require a gas certified person to swap it out. Other sites recommended getting any DIY work checked out and certified afterwards which is what we are doing.

So after many hours of profanity, mucky water, and banging of stuck pipes the new heat exchanger was installed. A pressure test according to the service manual was performed and all looked good. Reassembled everything and fired it up. Heat works, hot water, no loud banging or grinding noises, and no leaks or drips. Success I'd say. Just need to book in the expert for certification.

It was until Sunday night. A loud pop from the boiler and a resulting torrent of water ensued. Everything off, drained down the whole thing and a lot of mopping up.

Opening up the case, it seems that one of the holding clips for the heat exchanger wasn't where I left it. In fact it had come off completely Looking closely at the connection, it had slipped out of place because the O ring failed. Moving the pipe slightly the ring just fell out, split. It may have been a duff ring, or it may have been snagged when installing. Either way the pipe end has been filed smooth and a spare ring fitted.

Hopeflully Murphy has p*ssed off to bother someone else for a while. The new O ring seems to be holding ok during the pressure test. A couple more hours, then eas back the pressure, reassemble, and call the expert in.