New small hot water tank or combi boiler??

frugalfiz

My kitchen sink and the guest room above it are a long way from my hot water tank, so I waste loads of hot water drawing it through the long length of pipes. I reckon I run the tap for 20-30 seconds to get hot water, and probably do this around 10 times a day. I am considering having a small hot water tank with an immersion heater or a small combi boiler, just for that end of the house to feed the kitchen sink and the occasional use guest bathroom above. I don't have much space but I do have a cold water supply and oil supply to the aga in the kitchen. Have also considered back boiler to the aga, but I turn it off in the summer. Has anyone got any suggestions of cost and what would take up least space?
Thanks

HappyMJ

How about a Quooker or something similar? Instant hot water heated by electricity at the tap. It has a small 3 litre tank kept hot all the time and only costs a few pence per day to keep on standby. You get your hot water instantly rather than running through the water through many metres of pipe saving both energy and water.

frugalfiz

HappyMJ wrote: »

How about a Quooker or something similar? Instant hot water heated by electricity at the tap. It has a small 3 litre tank kept hot all the time and only costs a few pence per day to keep on standby. You get your hot water instantly rather than running through the water through many metres of pipe saving both energy and water.

Thanks for that, yes I did consider Quooker as an option, but I was advised by someone who sells them to check out the running costs. Quooker say they are only 3p a day to keep on standby, but do they cost a fortune to actually heat the water? I need to check that out. I might post a separate thread asking if anyone uses one and how much it costs.

Horizon81

You'll still wait a good 30 seconds or so for a combi to provide hot water. But a combi is for heating and hot water so you wouldn't need the heating side would you? I'm sure there will be hot water only solutions available.

Nevertheless, it begs the question why do you run the hot tap 10 times a day? If it's just to wash your hands then use cold water if you don't like waiting for the hot to be drawn through.

HappyMJ

frugalfiz wrote: »

Thanks for that, yes I did consider Quooker as an option, but I was advised by someone who sells them to check out the running costs. Quooker say they are only 3p a day to keep on standby, but do they cost a fortune to actually heat the water? I need to check that out. I might post a separate thread asking if anyone uses one and how much it costs.

The running costs are very similar to a kettle plus the 3p per day.

It always uses the same amount of energy to heat a certain quantity of water whether you use a kettle or a Quooker. The 3 litre Quooker is rated at 1600W and has a reheat time of 10 minutes. That assumes the water temperature starts at a certain temperature. It's therefore about 0.27kWh to heat 3 litres of water. You can look at your electricity bill to see what that would cost. My electricity rate is 10.855p/kWh so it costs 3p to heat 3 litres of water. You said you do that 10 times per day so that's 30p/day plus 3p and therefore £10 per month. You'd also use 30 litres of water per day.

You then need to compare that to your current set-up. How much water do you waste to get 6 litres of hot water? You need 6 as the water temperature isn't as high. How much energy was used to get that water hot? All that water left in the pipe is now wasted so you need to take that into account. Hot water in cylinder tends to be only 60 degrees so you still need to use a kettle to get boiling water.

frugalfiz

Horizon81 wrote: »

You'll still wait a good 30 seconds or so for a combi to provide hot water. But a combi is for heating and hot water so you wouldn't need the heating side would you? I'm sure there will be hot water only solutions available.

Nevertheless, it begs the question why do you run the hot tap 10 times a day? If it's just to wash your hands then use cold water if you don't like waiting for the hot to be drawn through.

Well, four of us live in the house, we all work from home and we have animals and so wash hands often, and someone is always eating so I have to wipe down surfaces and wash cups and stuff that don't always go in dishwasher (btw I don't have OCD - far from it!) but I do feel I waste a lot of hot water. Thanks for advice

frugalfiz

HappyMJ wrote: »

The running costs are very similar to a kettle plus the 3p per day.

It always uses the same amount of energy to heat a certain quantity of water whether you use a kettle or a Quooker. The 3 litre Quooker is rated at 1600W and has a reheat time of 10 minutes. That assumes the water temperature starts at a certain temperature. It's therefore about 0.27kWh to heat 3 litres of water. You can look at your electricity bill to see what that would cost. My electricity rate is 10.855p/kWh so it costs 3p to heat 3 litres of water. You said you do that 10 times per day so that's 30p/day plus 3p and therefore £10 per month. You'd also use 30 litres of water per day.

You then need to compare that to your current set-up. How much water do you waste to get 6 litres of hot water? You need 6 as the water temperature isn't as high. How much energy was used to get that water hot? All that water left in the pipe is now wasted so you need to take that into account. Hot water in cylinder tends to be only 60 degrees so you still need to use a kettle to get boiling water.

OK thanks for that calculation. Our water is heated by oil and that hot water lying in the pipe going cold really bothers me. I'm getting the Quooker brochure so will check it out. It's good that it is small and I like the idea that I won't need a kettle.

Horizon81

Since having a combi fitted I tend to use the cold tap to wash hands as it takes at least 30 seconds for the boiler to fire up from cold and start heating the water to a sufficient temp, and for it to reach whichever tap I'm at. If the heating is on (and thus the boiler is already hot) then this time is reduced, but obviously that's no good in the summer months.

I have a mate who's got more money and engineering skills than sense and he fitted a pump to his megaflow system that circulates hot water constantly round his hot water pipework so whenever you turn the hot tap on it only takes a second for the hot water to get from the circulating system to the tap. I believe it's the same sort of systems that hotels use. I suspect it's got a name but that may be a possibility depending on what set-up you have at the minute.

HappyMJ

Horizon81 wrote: »

Since having a combi fitted I tend to use the cold tap to wash hands as it takes at least 30 seconds for the boiler to fire up from cold and start heating the water to a sufficient temp, and for it to reach whichever tap I'm at. If the heating is on (and thus the boiler is already hot) then this time is reduced, but obviously that's no good in the summer months.

I have a mate who's got more money and engineering skills than sense and he fitted a pump to his megaflow system that circulates hot water constantly round his hot water pipework so whenever you turn the hot tap on it only takes a second for the hot water to get from the circulating system to the tap. I believe it's the same sort of systems that hotels use. I suspect it's got a name but that may be a possibility depending on what set-up you have at the minute.

The preheat function on a combi does a similar thing. It keeps the water in the heat exchanger in the boiler hot so when a tap is turned on you get hot water much quicker. The preheat function costs quite a bit to operate so most people turn it off.

Horizon81

HappyMJ wrote: »

The preheat function on a combi does a similar thing. It keeps the water in the heat exchanger in the boiler hot so when a tap is turned on you get hot water much quicker. The preheat function costs quite a bit to operate so most people turn it off.

That's true, I'd forgotten about that. I have an 'eco' and a 'comfort' function but keep it on eco for MSE reasons. I did try it on comfort once and the boiler very rarely fired up to pre-heat itself so I doubt it would have made a huge difference to the time taken for hot water to reach the taps. I never measured it.

elliot341

Hi, i wouldnt worry about spending hundreds of pounds on a quooker etc, I would look at getting a small instantaneous hot water heater. I had a Dafi (look on ebay) in line hot water heater installed in my downstairs wc as it had a really long run from the boiler (sounds like your issue). About £50 to buy, you may need an electrician to fit, but if you get the appropriate sized unit you'll only be heating up the water you use and your pipe runs will be a lot shorter and your water will be hot, instantly!