Hello. In order to convert my loft I need to get rid of the existing water tank (cistern) in the loft. It is a 4 bed house with conventional gas boiler and hot water cylinder in airing cupboard. Is the best way to do this to replace the hot water cylinder with a thermal store and thereby get hot and cold water both at mains pressure? Thanks in advance as any advice would be appreciated. Peter
Yes, that's the best option for maximum simultaneous flow rate to all taps. A cheaper option - as you probably know - is a powerful combi boiler. Disadvantage of the combi is that it'll only provide full flow to a single hot tap at a time (tho' you apparently can buy giant ones that'll cope with more, provided your mains water supply is also up to the job...) but the advantages are no hot storage tank taking up room, slightly lower energy costs (you heat only what you need) and endless hot water. I had this exact situation 10 years ago and opted for a combi. It's a 3/4 bed house with 3 bathrooms, and it's a very rare issue when two peeps need hot water at the same time. It chust hasn't been a problem for us at all in practice.
Thanks very much for your reply. I understand what you say about a combi boiler. Don't want to change the boiler at this time although it's 15 years old (Potterton Suprima) and adding extra room might increase contention. I was wondering if any plumbers could advise on product choice and maybe explain the difference between a thermal store and heat bank! I was also thinking that I could include a solar water heater in the system.
Rip it all out,boiler, hot water cylinder & tank then fit a large combi like a Valliant, something in the 37-40kw range. Expense now, considerably more efficient & a good flow of hot water, you benfit from the savings, add in weather compenating control you save even more.
At one time Heatbanks were not popular in the plumbing trade some years ago, designs have been improving over the years, but I have no idea as whether they are looked up on more favourably now.
Thanks again for replies. Boiler could probably do with replacing anyway although working fine now. I've always associated combis with contention and after loft conversion there willl be 3 bathrooms. Just 2 of us in the house most of the trime though, except when family decends. Thinking about contention - with a combi, if using a shower and another hot (or cold) tap is turned on the flow from the shower will be affected. With a thermal store the hot water must be heated via the heat exchanger as required, and the boiler must heat the stored water, so surely there is going to be the same problem. But I've always felt that it would be good to have a system that allowed stored cold water to be warmed up a bit via a solar panel so that when required to be heated less fuel is needed and it would be quicker. Obviously a combi is required to heat ice cold water from the mains. Is this a big deal? Incidentally the central heating is 10mm microbore. I am near Chichester, West Sussex.
If your considering solar then you'll need to plan space for a cylinder. You can have either a vented or unvented cylinders, personally I would go for the unvented given the benifits of that type of system. Your boiler would suffice for the job but whilst you altering the system you may want to consider a modern HE boiler and all the benifits that brings. As an alternative you could consider something like the Vaillant 937 powerstore combination boiler. basically its a combi which has a storge tank mounted behind it to cope with the additional water demand and is suitable for a two bathroom house. Downside to these is they are bulky and need careful consideration on siting. Have a look at the Vaillant web site for more details, their site will also give you some options/ideas for renewables and show you how the differnt systems work.
No... A thermal store is a open vented store that heats different applications through coils and heat exchangers, example: a hot tub, hot water, solar, log burners, htg etc etc could all be incorporated. An unvented hot water storage cylinder is mains fed, direct or indirect, The question is this... How many bathrooms do you have? What's in them? Occupants? Flow rate? Pressure? Combi's are only good for 1 decent shower without fluctuations, a good one 15ltrs min, a good shower 10 ltrs min, leaves you 5 for everything else, it's that simple,
Forums
Facebook
Twitter
You Tube
Instagram
Shop