Hey all, I'm trying to get my head round this. We've got an ageing system with an 18 year old 24kW system boiler and a similarly aged megaflow water tank. The boiler has been on its last legs for a while and I want to replace it. The problem is that I don't want it in the same place as it is now as it's on a wall that we will eventually be knocking down as part of a small extension. I'd rather not keep the boiler in the kitchen because it eats up so much space. I think there is a place I could move it to but it would require moving some partition walls around, building a cupboard and having a flue extension through a small toilet only bathroom. The other option that I thought might be good would be to go with a large combi boiler e.g. a Worcester Bosch 30kW (or even the big 50kW) combi boiler and potentially installing that in the cellar where the Megaflo currently is. The flu would need to be piped up the side of the house from a foot or so underground and through some tiles but I've long thought that would be a much more practical location. It would free up a lot of space in both the kitchen and the cellar.
The thing is, whenever I've had someone out to do maintenance on our current boiler and I've mentioned the idea of a combi, they've always said it's a terrible idea. We had a British Gas engineer out today and he said he'd strongly advise against it. I just don't quite understand why though. It's a 5 bed end-of-terrace ~2000 sqft house. 2 adults, 2 (soon to be 3) young kids (eldest is 3). I thought the main issue with combi systems is if multiple people are calling for hot water at the same time. But no two showers or baths are ever run at the same time. As it is, with a water tank, the pressure still drops by a noticeable amount if my wife happens to run the tap downstairs while I'm having a shower. So if two showers *were* being used at the same time, the overall water pressure would be down anyway. As it stands, if we're planning on having a shower or a bath at a different time than normal, we have to remember to boost the hot water beforehand (or after depending on the timing so that there's enough for the kids' bath later) and one thing I used to love when I lived in a flat 20 years ago was the endless hot water from the combi boiler. So why do these engineers keep saying it's a terrible idea. Am I missing something?
I had a look just now for replacement boilers, both system and combi and it looks like they cost about the same for similar power including (standard) installation. So it strikes me that maybe the best option for me would be to get a new combi boiler installed where our Megaflo is right now, freeing up all that space in the kitchen and the tiny cellar. Then, if for whatever reason, it's as big of a disaster as these British Gas engineers say then surely I could get a new water tank installed in the loft at a later date (in unused space) and run the combi boiler effectively as a system boiler?
The thing is, whenever I've had someone out to do maintenance on our current boiler and I've mentioned the idea of a combi, they've always said it's a terrible idea. We had a British Gas engineer out today and he said he'd strongly advise against it. I just don't quite understand why though. It's a 5 bed end-of-terrace ~2000 sqft house. 2 adults, 2 (soon to be 3) young kids (eldest is 3). I thought the main issue with combi systems is if multiple people are calling for hot water at the same time. But no two showers or baths are ever run at the same time. As it is, with a water tank, the pressure still drops by a noticeable amount if my wife happens to run the tap downstairs while I'm having a shower. So if two showers *were* being used at the same time, the overall water pressure would be down anyway. As it stands, if we're planning on having a shower or a bath at a different time than normal, we have to remember to boost the hot water beforehand (or after depending on the timing so that there's enough for the kids' bath later) and one thing I used to love when I lived in a flat 20 years ago was the endless hot water from the combi boiler. So why do these engineers keep saying it's a terrible idea. Am I missing something?
I had a look just now for replacement boilers, both system and combi and it looks like they cost about the same for similar power including (standard) installation. So it strikes me that maybe the best option for me would be to get a new combi boiler installed where our Megaflo is right now, freeing up all that space in the kitchen and the tiny cellar. Then, if for whatever reason, it's as big of a disaster as these British Gas engineers say then surely I could get a new water tank installed in the loft at a later date (in unused space) and run the combi boiler effectively as a system boiler?
Last edited:
