HVAC Questions? Ask an HVAC Expert for Answers ASAP
Hello, welcome to the Technical section in JustAnswer; my name is ***** ***** I will help you today.If you're removing your cold water storage cistern when building into the loft then you have only two realistic options for hot water:1. A combi boiler;2. An unvented vessel.The very first thing to do is measure your incoming cold water flow rate. This won't necessarily redirect your plans, but you might have to include an accumulator in your budget if the incoming flow rate is poor.The power of the combi, or capacity of unvented vessel, is derived from the number of bathrooms you have.Ask me some more specific questions and I'll answer them.BTW, I looked at your November topic, and James posted on there twice but you didn't respond either time._____If you receive a phone call offer, please ignore it - these are system generated and outside my control. My understanding is that you won't be charged if there's no phone call.
Hi John21 litres per minute (minus losses through pipework) will do very nicely for one shower, but if you were ever to have two or three people showering at once then of course they would be sharing that flow rate.Regarding average consumption, 46-60 litres pay day is reasonable, so the 300 litre cylinder would support 6 people, nominally. You could have a smaller cylinder and simply re-heat it more often, but it's your call. Does the Gledhill product have a full warranty for the entire 25-year warranty period? Are there any exclusions?Are you installing the cylinder into the loft? I inferred from your earlier comment that the loft was going to become living space.
Gledhill products tend to be a bit pricey. I would look around and compare prices and warranties.Whatever you install, I recommend that you make provision for replacing it within the warranty period. If it fails earlier than expected, the manufacturer won't pay for the labour involved in replacing it, so you don't want to make life difficult by, for example, building a wall in front of it. _____Regarding the flow rate, if you didn't measure it at an open tap close to the main stop cock, it's not a representative measurement. I would expect a hose to be restrictive, which is good news of course, but without an objective measurement you'll be guessing. Your plan to use 22mm pipework from the stop cock to the cylinder might help; it certainly can't do any harm.
My bad - I neglected to answer your question.There's absolutely no reason not to site the cylinder higher than the boiler. With a gravity primary it would be necessary, but in a fully pumped system it won't impair performance in any way - you can put either of them wherever you like.The reason I queried the loft was simply to clarify my understanding - I had imagined that you're doing a loft conversion and wondered how the cylinder fitted into that plan. A 300 litre cylinder is tall, but not too tall to go into an airing cupboard, and that's usually a far more accessible location for maintenance purposes. For example, if you migrate to solar PV power and start to use the immersion heater more, then the immersion will have a shorter lifespan and you'll curse yourself if it's a PITA to work on the cylinder. I'm thinking of the big picture, for your sake._____To explain my point about the warranty - I wasn't suggesting that you would replace it the day after the warranty expires. Very much not - get the most you can out of it! But some products fail within the warranty period, and if that happens you'll get a free cylinder from the manufacturer but you won't get free installation. Also, with Gledhill, I've always had to buy the replacement so that I can swap it in and then get the faulty one sent back to the factory. After analysing the fault, the refund is issued. All I'm saying is please don't be under any illusions about the warranty; you will be covered, but you'll have to lash out for a new one, and the cost of installation/replacement, yourself.
If competently installed then they never burst. You don’t want that scenario, because the grim reality is that an unvented vessel that overpressurised owing to an incompetent installation could leave your house via the roof.It can’t stop working, per se, but there are five essential external components that can fail, plus the immersion heater(s), plus the external pipework, so maintenance of all of that needs to be considered.
It can leak, and one day it will leak and will need to be replaced. It’s only a matter of time.
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