Getting hot water to sink, to wash hands, methods?

[ericmark]

It takes 60 seconds to run off cold water before hot arrives, it also takes 60 seconds to boil a cup boiler, (50 seconds to boil 10 seconds to be ejected into the cup) so it seems hardly worth it to fit a local water heater to wash hands down stairs. Specially since I would loose cupboard space.

However this time of year we tend to run out of hot water, solar panels heat the water once battery is full, but this time of year, we get bad days, yesterday purple line the battery never charged from solar, only the off peak charged battery, which lasted us until nearly 8 pm so not bad, but by today water is cold, and it seems likely again no solar to reheat it. Once the central heating is running, we can't stop the DHW being heated, and the central heating does the whole tank, where the immersion only does top foot, so heated with central heating hot water lasts 3 days, but not with the immersion heater.

So the question is, what, if anything, to do about it? Options are:-
1) Under sink boiler.
2) Longer immersion heater.
3) Program a boost time into the iboost+
4) Swap the iboost+ immersion heater controller for a time clock and use off peak.
5) Just boil a cup of water when we have no solar. i.e. do nothing.

The problem with the boost time, is we don't realise we need it, until after the water has cooled, most days we get a pattern like this and the flat top to the state of charge curve means we had more solar than required, so immersion heater has heated the DHW, so just a few days in Autumn and Spring when we run out. Typically we use around 0.6 kWh per day to heat the DHW, so hardly worth spending out a lot of money to cover the days when we run out, but I can't be the only one with this problem. So any idea I have not thought about?

 

[noseall]

It takes 60 seconds to run off cold water before hot arrives, it also takes 60 seconds to boil a cup boiler, (50 seconds to boil 10 seconds to be ejected into the cup) so it seems hardly worth it to fit a local water heater to wash hands down stairs. Specially since I would loose cupboard space.

However this time of year we tend to run out of hot water, solar panels heat the water once battery is full, but this time of year, we get bad days, yesterday purple line View attachment 354885the battery never charged from solar, only the off peak charged battery, which lasted us until nearly 8 pm so not bad, but by today View attachment 354886 water is cold, and it seems likely again no solar to reheat it. Once the central heating is running, we can't stop the DHW being heated, and the central heating does the whole tank, where the immersion only does top foot, so heated with central heating hot water lasts 3 days, but not with the immersion heater.

So the question is, what, if anything, to do about it? Options are:-
1) Under sink boiler.
2) Longer immersion heater.
3) Program a boost time into the iboost+
4) Swap the iboost+ immersion heater controller for a time clock and use off peak.
5) Just boil a cup of water when we have no solar. i.e. do nothing.

The problem with the boost time, is we don't realise we need it, until after the water has cooled, most days we get a pattern like thisView attachment 354888 and the flat top to the state of charge curve means we had more solar than required, so immersion heater has heated the DHW, so just a few days in Autumn and Spring when we run out. Typically we use around 0.6 kWh per day to heat the DHW, so hardly worth spending out a lot of money to cover the days when we run out, but I can't be the only one with this problem. So any idea I have not thought about?

We located our CH boiler centrally between (and above) both upstairs showers, as these have the greatest demand for hot water. Furthest away are the WM, DW which are both cold fill. Admittedly, it takes a while for it to reach the kitchen sink, but we mostly use the DW to wash the dishes.

 

[bernardgreen]

The layout of this cotttage meant pipe runs would be very long if a "conventional " system was used.

The optimum was to have two vented hot water cylinders. One in the kitchen and one in the bathroom.

The one in the bathroom also has a "shower coil" which heats mains pressure water for the shower.

 

[Madrab]

I guess the other question is, is HW required to wash hands effectively, or does cool or cold water clean hands just as effectively.

Worth a search online .... some interesting reading ... seems it's not as important as once thought and is more a personal preference and generations of being told it is.

 

[Murdochcat]

Making electrical or plumbing changes will cost.

How much hot water do you think you use like this per year?

 

[jackflashh]

Do you need hot water to wash your hands?

 

[Deluks]

I cant stand washing hands in cold water, (I have been called a 'clean freak' by my mates)


What about something like the tap below? I have used similar on a campsite, the water was lukewarm but better than freezing cold. Bear in mind this was an outside sink, fed by a blue pipe running across a field, so the water would've been very cold to start with.

Or how abuot a hot water urn? That keeps heated water stored inside it.

Another idea is an electric shower unit, fitted to a wall, but with the shower head end plumbed into a tap. Could require some experimenting as the pressure could be too high at the tap end.
A push button on/off would be less frustrating than those big plastic knobs you get on wall mounted water heaters.

https://www.amazon.co.uk/Pudin-Electric-Instant-Stainless-Facilities/dp/B06XCS4MQT/ref=asc_df_B06XCS4MQT?tag=bingshoppinga-21&linkCode=df0&hvadid=79920808416481&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4583520383345695&th=1

 

[ericmark]

That looks good, although the report that it's that hot you could make a brew from it, is a bit off putting.

 

[Harry Bloomfield]

Another idea is an electric shower unit, fitted to a wall, but with the shower head end plumbed into a tap. Could require some experimenting as the pressure could be too high at the tap end.

You cannot subject an electric shower, to mains pressure, by fitting a tap to the outlet, it would blow the pressure safety. The water input, needs to have the tap, or as you suggest - a push button, plus solenoid to control the water in.

 

[cdbe]

We have an unvented cylinder, all the hot water is piped in plastic radials from the cylinder outlet. 15mm bath and showers, 10mm for taps. The tap in the bathroom next to the cylinder is less than 1 second to scalding, downstairs WC 7 seconds, kitchen 9 seconds.

 

[ericmark]

The system I had in my old caravan would work, there was a small tank of hot water under the sink, and a special tap that turned the water on into the tank, outlet being just faucet, which would drip as the water heated up and expanded, however the physical size is a problem, only 7 litres but very thick insulation, so hardly any room in under sink cupboard. I actually swapped the element to 1 kW which proved ample.

But feeding from the hot water supply, it would mean in summer even more water drawn before getting hot water, once the unit has been switched off.

Best would be renew pipe work for a smaller diameter, well lagged, but that would involve dropping the ceilings to get access, so for the few day Autumn and Spring when we find our selves without hot water hardly worth the effort.

The iboost+ it seems does have an option to heat from off peak, I have tried reading the instructions, not very clear, but again it is only a few days where no DHW, and it seems a bit OTT to set the iboost+ to heat with off peak 365 days a year, when only really needed for maybe 21 days a year, by time we realise the water is cold, it is a bit late.

Seems no real option without silly expense, but there may be some thing I just had not thought about.

 

[brig001]

It takes 60 seconds to run off cold water before hot arrives, it also takes 60 seconds to boil a cup boiler, (50 seconds to boil 10 seconds to be ejected into the cup) so it seems hardly worth it to fit a local water heater to wash hands down stairs. Specially since I would loose cupboard space.

There are some ideas here which might help with this part of the question

Pumped hot water loop alternative

Our bathroom is a long way from the megaflow tank and it takes a while for the water to run hot at the tap. No problem for filling the bath, but would be nice to have warm water available immediately at the sink Is there a way to fit a valve under the sink piped to the toilet fill so that it...

www.diynot.com

Brian

 

[ericmark]

At last some sun, water reports as hot, and used 0.60 kWh today, over the week it shows 2.92 kWh, which raises the question why use an iboost+ to start with? Well we have been told so many times, how costly it was to heat DHW with electric, I just believed what had been said, and I know my oil boiler in summer (20 kW) has to fire up 4 times a week, at ½ hour each time, and it actually ran for 20 minuets each time, so thought the electric would use the same amount of energy.

I have been reading the instructions for the iboost+ is says:-but this seems to defeat the whole idea of having the iboost+, in winter the central heating is running, so no way to stop central heating from heating the domestic hot water, in summer the solar does it's job, the figures the manual shows seem great but in real life that is 0.60 kWh today, yesterday not much sun so zero, 2.92 kWh last 7 days, 14.88 kWh last 28 days, and 98.13 kWh in total and been fitted nearly a year.

So in a year saved just over £30, so will take 10 years to pay for its self. Well if I used off peak, saved £8.80 so over 30 years.