New boiler options

[Kerberos]

Our boiler is on its last legs AND isn't really big enough to heat our house properly.

So, I'm thinking it might be time to invest in a new one. Given it'll be a long term investment as we're not planning to move from here, does anyone have any wise words of advice? Heat exchangers, solar panels - any of those worth thinking about just yet?

I could fall into a Google rabbit hole but thought I'd ask first if the wise people of mumsnet had any directional advice?

Why not just a regular combi boiler ?

Yeah we probably will just go for a standard combi. Just wondered what other options there were out there that's all :)

I'll throw into the mix , a sealed unvented system using a system boiler not a combination one. My dh tells me they are more efficient and will give you a longer term reliability .

if you can make it survive another year there should be hydrogen ready boilers starting to come on the market

Yeah right hydrogen in the next 12 months, will it be cheaper to run than a mains gas boiler ?

its getting introduced into the mains gas system so will just slowly begin to take over, modern boilers can already handle the first few years of switchover but will need to be replaced once around 40% plus is being included. Prototypes are out now so we expect them to be brought to market pretty soon so worth the wait if its not super urgent.
airspurce heat pumps are good if you don't mind loss of space outside and have a newbuild/ highly insulated house, run with pv panels and something like a sunamp battery to store excess generated electric.

I wouldn’t bet on Hydeploy being quite so soon. The trials at Keele are very successful so far, but were delayed over lockdown and there is a lot of testing still ongoing.

I hate combis although I have the luxury of space for an airing cupboard. Here in not-London we get occasional power cuts, more on windy days; means I can plan ahead and heat the water while the power is there.

also a useful place to dry towels (= less washing) and finish off any slightly damp washing.

hydrogen ready just means they run off mains gas until you want them to switch over ..

Air source heat pumps take up little space outside. It's an air con unit mounted on the ground. There are grants available ATM, search Green Homes Grants. It will work best with extra insulation. Mine is cheap as chips to run, partly because you can get special tariffs for them.

Op wants a boiler now , I believe hydrogen will be the next fuel source for the masses ( including transport) but it’s a long way off , the experts are predicting mid 2030’s. But if the op buys a hydrogen ready boiler next year ,then by the time he converts it to hydrogen ( it won’t be a big job to covert from natural gas to hydrogen ). It will be about 15 years old and need replacing anyway.

So for the time being natural gas is the cheapest option. Or wood if you get it for free 👍

Plus hydrogen is expensive to produce atm, so more advances are needed to bring the costs down .

how many bathrooms do you have, and how many people are likely to live in the house?

when was it built?

We've been coaxing it along for the last 6 years - the final straw for me came when the latest really cold weather hit! Started this thread then DP tells me he'd turned the temperature down on it... turned it back up and it's seeming warmer so might not be the emergency just yet although given its age and the fact we've been told it was a model only ever sold in B&Q for DIY installation it won't be long!

House is 1960s, 4 bed detached. 5 of us living here for the foreseeable future.

Green grants sound interesting, did some reading up after starting this thread. Hydrogen wasn't mentioned, so am heading that way for a Google now.

We are redoing our house at the mo - will be 5 bed semi detached with 3 bathrooms, 5 people - 3 daughters who imagine once all teens will use bathrooms a lot! Planning to put a combo boiler in along with an indirect water cylinder - yet to research exactly what but know of megaflows as a potential option.

@Mummyto3gorgeousgirlies

We are redoing our house at the mo - will be 5 bed semi detached with 3 bathrooms, 5 people - 3 daughters who imagine once all teens will use bathrooms a lot! Planning to put a combo boiler in along with an indirect water cylinder - yet to research exactly what but know of megaflows as a potential option.

A large unvented cylinder is probably the best choice, provided your incoming water flow is high enough. What will you use the combi HW for?

Our house is an old 5 bedroom, 2 bathroom and downstairs loo. 2 showers and a bath. Very good pressure into house but cylinder was too small to fill a bath and one shower was a v old electric.

We’ve an oil boiler and took out the old water tank to put in a megaflo type cylinder. It’s fab, you can run both showers, the taps etc and there’s no sudden rushes of cold in the shower.

Our brand new combination in previous house ...you couldn’t fill the kettle while someone was in the shower and the bath took forever to fill.

We looked at a heat pump but not suitable for this old house really.

Water pressure not great here, which might be part of the problem. More to Google :)

Are you sure you don't mean "flow?"

An older house often needs a larger supply pipe run out to the pavement.

It is easier than you think.

@PigletJohn I think the mega flow in an unvented cylinder. Thought need boiler too to
a) heat the water sent to indirect cylinder -
b) for the central heating
C) to ensure that if cylinder runs out of hot water due to three baths or showers going at the same time water comes from alternative supply
Happy to get advice if better options - thanks!

the combi HW is separate from the cylinder HW. It's possible, if necessary, to have one or more showers or taps run off the combi instead of the cylinder.

If you have a 30kW boiler (probable) it will re-heat the cylinder pretty quickly. I expect you will have an upper and a lower immersion heater so that in the infrequent cases when the boiler is out of order, you can heat the cylinder in advance of bathtime, though this will be much slower than the boiler.

Modern practice is to have a cylinder around 250 litres. A bath takes around 100 litres.

@PigletJohn

the combi HW is separate from the cylinder HW. It's possible, if necessary, to have one or more showers or taps run off the combi instead of the cylinder.

If you have a 30kW boiler (probable) it will re-heat the cylinder pretty quickly. I expect you will have an upper and a lower immersion heater so that in the infrequent cases when the boiler is out of order, you can heat the cylinder in advance of bathtime, though this will be much slower than the boiler.

Modern practice is to have a cylinder around 250 litres. A bath takes around 100 litres.

Thanks for this - so what is difference with a direct and indirect cylinder? Thought the indirect required the boiler to heat and tank just maintained it hit

Hot 🤦🏻‍♀️

any cylinder you buy is pretty sure to be an indirect.

The boiler heats water and circulates it around the radiators and/or the heat exchanger coil in the cylinder. This primary water does not mix with the water in the cylinder that goes into the taps. The cylinder can deliver hot water to the taps as fast as the supply pipe can deliver it to the house. In some cases it may be as much as 20 litres per minute.

A combi boiler has its own heat exchanger, which the boiler heats, and which passes heat to water from the supply which goes into the hot water taps. The primary water does not mix with the tapwater.

A modern combi can usually deliver around 12 litres per minute of hot water (a bit less in winter, or less hot), provided the water supply has sufficient flow. This is sufficient for a good strong shower (or two rather weedy ones)