do you need to change piping going from low P to mains P? what if pipes from 1971?

Maybe have a read of this discussion, if you are extending the length of the hot water feed.

https://www.geekzone.co.nz/forums.asp?forumid=141&topicid=285926

I wonder if you'll have problems with a drain. I had our hot water cylinder moved from a cupboard in the bathroom to the ceiling cavity, which worked great. They put a drip tray down, built a wooden frame around it to make it earthquake safe, we have more cupboard space.

Batman:

do you need to change piping going from low P to mains P? what if pipes from 1971?

Hot water pipes from HWC to shower and bath are lagged 3/4" copper.  While that meant that you could fill the tub quickly, the shower was still hopeless, first attempt to sort that was to replace the shower mixer with a venturi type - which gave some improvement, but by modern standards was still pretty useless. Inline booster pump sorted that, but from my experience it was a bit tricky to set the automatic flow switch "just right".

Downside to the 3/4 inch pipe is there's more than twice as much water volume per metre of pipe than with 1/2", and more copper to heat up - so takes longer to get hot water through to a tap, and there's more energy wastage.

It's something I'll talk to the plumber about.  As all those pipes are easily accessed in the sub-floor space, it shouldn't be a big job to replace them. 

We have poor mains pressure from the street and decided to be in charge of our own destiny... We installed a 900 litre tank filling from the street (which also could be an emergency water supply in a natural disaster) and a pump rated to 180L/m that sits before the hot water cylinder and cold feeds. We have a lot of pipe from the hot water cylinder (probably at least 15m) but at that flow rate you can get hot water in like 3 seconds if you crank open the tap... But be careful, if you switch from the bath nozzle to the shower head, the shower head becomes an airborne missle flying around the bathroom.

Fred99:

Any teenager who takes a 40 minute shower heated with gas should be tied to a tree along with their daft parents and hosed down with cold water until they all come to their senses.

pih:

Fred99:

 

Any teenager who takes a 40 minute shower heated with gas should be tied to a tree along with their daft parents and hosed down with cold water until they all come to their senses.

 

This is actually one of the benefits for having instant gas HW (and/or pumped tank water). If my daughter is in the shower too long and ignores repeated warnings I just flip the breaker and the pump stops. Or the water goes cold. I get to choose which. Power is back in my hands now!

You haven't won yet.  Wait 'til you're old and doddery, but still deemed to be capable of looking after a house full of spoiled rugrats while daughter takes "mental health break" at some tropical luxury "wellness" resort for a week, blaming the entire inability to cope on the mental harm you caused her by water-torture when she was a teen, even used that to emotionally blackmail you into paying for the trip.

Or heaven forbid if you cut the water off at the time she needed to rinse off some concoction of corrosive chemicals used to make hair straighter or curlier, darker or lighter, various colours, or combinations of any of those,  emerged from the shower screaming with head covered in something that looked like dried alfalfa sprouts before it all dropped on the floor.

What about a heat pump system?

https://www.ecospring.co.nz/

Been looking at this myself for the same reason - 23 year old low pressure system and upgrading Kitchen and Bathroom soon.

James Bond:

 

What about a heat pump system?

 

https://www.ecospring.co.nz/

 

Been looking at this myself for the same reason - 23 year old low pressure system and upgrading Kitchen and Bathroom soon.

 

My preference - if wanting to spend more - would be to install solar water.  The house next door has had a system for >30 years, it's needed no maintenance, I've known both owners of the house over that period, it's very efficient, less so in winter of course, but still a huge annual power saving.  We've got a large north-facing gable that should be ideal to put solar water panels on.

I think heat pump hot water might be marginal in terms of cost and lifespan / payback period.  Only two of us here most of the time.

Fred99:

 

James Bond:

 

What about a heat pump system?

 

https://www.ecospring.co.nz/

 

Been looking at this myself for the same reason - 23 year old low pressure system and upgrading Kitchen and Bathroom soon.

 

 

My preference - if wanting to spend more - would be to install solar water.  The house next door has had a system for >30 years, it's needed no maintenance, I've known both owners of the house over that period, it's very efficient, less so in winter of course, but still a huge annual power saving.  We've got a large north-facing gable that should be ideal to put solar water panels on.

 

I think heat pump hot water might be marginal in terms of cost and lifespan / payback period.  Only two of us here most of the time.

 

In Australia, the figures work out that a PV system feeding a heat pump hot water cylinder is considerably better than direct solar heating of the hot water.  The heat pump multiplier more than makes up for the loss of energy in converting to electricity and back again.  There seems to be a serious competitive market over there for smart systems to do that.  I have no idea how well the figures would translate in NZ.

Fred99:

 

Any teenager who takes a 40 minute shower heated with gas should be tied to a tree along with their daft parents and hosed down with cold water until they all come to their senses.

Fred99:

 

You haven't won yet.  Wait 'til you're old and doddery, but still deemed to be capable of looking after a house full of spoiled rugrats while daughter takes "mental health break" at some tropical luxury "wellness" resort for a week, blaming the entire inability to cope on the mental harm you caused her by water-torture when she was a teen, even used that to emotionally blackmail you into paying for the trip.

 

Or heaven forbid if you cut the water off at the time she needed to rinse off some concoction of corrosive chemicals used to make hair straighter or curlier, darker or lighter, various colours, or combinations of any of those,  emerged from the shower screaming with head covered in something that looked like dried alfalfa sprouts before it all dropped on the floor.

🤣🤣🤣

Thanks, @Fred99, you've made my day!

Fred99:

There's no reticulated gas here (Chch), and I'd rather reduce our CO2 footprint where possible. I'll investigate options for solar. 

Any teenager who takes a 40 minute shower heated with gas should be tied to a tree along with their daft parents and hosed down with cold water until they all come to their senses.

Finally decided I better get around to dealing with leaking HWC, was starting to fill buckets too fast

Called plumber this morning, was here within 30 mins, 300l mains pressure cylinder can go in the basement, will be delivered and installed in a couple of hours. Boy sparky can wire it up saving a few $. Plumber will sit in on a precast slab they'll supply.  

I can remove the old cylinder later - to create new cupboard space.

Fred99:I can remove the old cylinder later - to create new cupboard space.

 

..and sell it to a scrap metal dealer for all the copper.

Don't forget to then use the existing 230v feed to the cupboard to connect up one of those little wardrobe heaters and you are away laughing.