Hi All, moved house a couple of years ago. had a few issues with central heating - to be honest it’s an old system, CH mix of 15mm & microbore, Some radiators don’t heat up, others museum pieces and not in a good way. I plan to get the whole lot ripped out and replaced. A few weeks ago, hot water packed up. Wife phoned up boiler manufacturer- they asked a few questions, resulting in suggestion was external pump broke. Looked like no heat travelling from boiler to tank. No issue I thought - got a new grundfos, and got a man in to change. system drained, pump changed, refilled, still doesn’t work. I should add at this point that a lot of space around the tank was boxed in to form a bathroom cupboard. Access to the tank did not appear to be a design consideration for this in any way. There were two pumps present which should have given some indication something was odd but... So... After the plumber left, I removed all the boxing in, and, much to my wife’s utter delight, some of the flooring from next to the boiler. I’m not in the industry but reading up online it looks like what we have is not a normal tank but a “thermal store” from around 1990. The obvious answer to my problems is to rip it all out and start again. BUT - ideally I’d like to delay that until I’ve had some building work done to convert the garage - with a view to whacking a floor standing combi in there when the space has been converted. We are currently living with no hot water, there is no immersion heater in the store, and I’m having issues trying to find someone experienced in these old heaps who could have a look and possibly get it running for a few more months to buy me time to move forward on the garage conversion.. It struck me that whacking an immersion heater in might buy me some time, but I’m worried that if that was a good idea, I can’t fathom why it wouldn’t have been done already... Any thoughts?