Low pressure Hot water cylinders

Forums › Home Workshop DIY › Low pressure Hot water cylinders

blackjack17

936 posts

Ultimate Geek

# 251687 6-Jul-2019 19:56

Have just brought a 1920s house and it has a low pressure hot water cylinder. Looks to be relatively new 2009. and all the plumping has been replaced (as has the electrics)

So what does this mean? Showers with no pressure? When we tried the taps it felt normal.

It is also only a 135L one.

Does any one know how much it would cost to replace with a mains pressure full size one?

1 | 2

3101 posts

Uber Geek

Trusted

# 2271148 6-Jul-2019 19:58

One person supports this post

To me it means your shower won't feel like a deluge/water blaster. There are options out there to replace it with Infinity running off LPG or Natural Gas.

Aredwood

3885 posts

Uber Geek

Subscriber

# 2271150 6-Jul-2019 20:08

Just try the shower and see how it performs. Just dont expect a water blaster. Although if you are used to mains pressure, you would probably be disappointed no matter what.

Biggest problem is usually really low flow rates to the kitchen and basin taps if they are single lever mixers. A correctly setup shower can still deliver 10L per min on low pressure. It definitely helps that the cylinder is in the ceiling.

Without seeing the job, budget 2.5K plus electrical costs for converting to mains pressure electric or LPG.

DjShadow

3101 posts

Uber Geek

Trusted

# 2271152 6-Jul-2019 20:11

Aredwood: Just try the shower and see how it performs. Just dont expect a water blaster. Although if you are used to mains pressure, you would probably be disappointed no matter what.

Biggest problem is usually really low flow rates to the kitchen and basin taps if they are single lever mixers. A correctly setup shower can still deliver 10L per min on low pressure. It definitely helps that the cylinder is in the ceiling.

Without seeing the job, budget 2.5K plus electrical costs for converting to mains pressure electric or LPG.

Have a look on Trademe under "Services", I've seen in the past a number of plumbers doing an all inclusive offer for switching to Gas/LPG

nickb800

2325 posts

Uber Geek

Trusted

# 2271164 6-Jul-2019 20:13

As above - give the shower a go first. If it's not good enough, then an upgraded shower head may help - Methven satinjet can deliver a great shower on a low flow/pressure

blackjack17

936 posts

Ultimate Geek

# 2271165 6-Jul-2019 20:14

Aredwood: Just try the shower and see how it performs. Just dont expect a water blaster. Although if you are used to mains pressure, you would probably be disappointed no matter what.

Biggest problem is usually really low flow rates to the kitchen and basin taps if they are single lever mixers. A correctly setup shower can still deliver 10L per min on low pressure. It definitely helps that the cylinder is in the ceiling.

Without seeing the job, budget 2.5K plus electrical costs for converting to mains pressure electric or LPG.

The cylinder isn't in the ceiling it is in the basement.

Also no gas on the street and my understanding LPG is pretty expensive for water heating isn't is?

Aredwood

3885 posts

Uber Geek

Subscriber

# 2271168 6-Jul-2019 20:18

blackjack17:
Aredwood: Just try the shower and see how it performs. Just dont expect a water blaster. Although if you are used to mains pressure, you would probably be disappointed no matter what.

Biggest problem is usually really low flow rates to the kitchen and basin taps if they are single lever mixers. A correctly setup shower can still deliver 10L per min on low pressure. It definitely helps that the cylinder is in the ceiling.

Without seeing the job, budget 2.5K plus electrical costs for converting to mains pressure electric or LPG.

The cylinder isn't in the ceiling it is in the basement.

Also no gas on the street and my understanding LPG is pretty expensive for water heating isn't is?

Definitely not so good with the cylinder underneath the floor.

LPG water heating is likely cheaper if you are on a Low User power pricing plan. Also depends on if you can get cheap night rate power in your area.

DjShadow

3101 posts

Uber Geek

Trusted

# 2271169 6-Jul-2019 20:23

Also remember gas is heat on demand, you are not paying power to keep your cylinder hot all day when it's not in use.

Scott3

652 posts

Ultimate Geek

# 2271199 6-Jul-2019 22:13

As others have said, Give it a try. Low pressure hot water cylinders are extremely common in New Zealand. You probiably have used one in a motel or similar without even knowing.

7.6m of head is sufficient to give a decent shower, especially when used with a mixer (typically methven brand) and shower heads that are designed for low pressure systems.

Long pipe runs, and gains in elevation can make a shower very weak.

My parents house has a low pressure, atmosphere vented (less than the 7.6 meters of head you get from a relief valve) cylinder. This is the typical set up for cylinder plumbed to the wet back of a wood fire.

The down stairs shower is fine, but the upstairs one sucks (very long pipe run & elevation gain).

DjShadow:

Also remember gas is heat on demand, you are not paying power to keep your cylinder hot all day when it's not in use.

True, but the heat losses are kinda small, especially on standard user power charges.

For modern cylinders, at the 135L size, MEPS requires that they have a standing loss of less than 1.4Kwh/day at a temperature differential of 55Deg. This is pretty much a worst case, and most cylinders will preform better than the minimum, and the 55 degree temperature differential is quite a lot. At minimum MEPS proformance, and my marginal power price of 15.53c/kWh, that works out to $80 per year. That's a less than bottle rental (for 45kg LPG Bottles), and a lot less than the monthly fee for a natural gas connection.

DarthKermit

5063 posts

Uber Geek

Trusted

# 2271206 6-Jul-2019 22:28

2 people support this post

One advantage of low pressure is they generally last one hell of a lot longer than mains pressure cylinders. They also don't need as many extra parts for pressure regulation, etc.

Bung

3067 posts

Uber Geek

# 2271208 6-Jul-2019 22:35

blackjack17:
Have just brought a 1920s house and it has a low pressure hot water cylinder. Looks to be relatively new 2009. and all the plumping has been replaced (as has the electrics)

Regarding the plumbing, the fittings certainly look recent but black piping?? @Aredwood is there an OK black pipe? I immediately think Dux Qest.

blackjack17

936 posts

Ultimate Geek

# 2271237 7-Jul-2019 04:35

Bung:
blackjack17:
Have just brought a 1920s house and it has a low pressure hot water cylinder. Looks to be relatively new 2009. and all the plumping has been replaced (as has the electrics)

Regarding the plumbing, the fittings certainly look recent but black piping?? @Aredwood is there an OK black pipe? I immediately think Dux Qest.

It isn't dux west. Have already checked that one out. But thank you

Lee13

33 posts

Geek

# 2271238 7-Jul-2019 06:31

Some excellent advise from others
I'd like to mention CLR the shower rose or head
Minerals build up over time and reduce the flow I have done it and had been amazed

kotuku4

297 posts

Ultimate Geek

Lifetime subscriber

# 2271279 7-Jul-2019 11:05

We have low pressure. When built the subdivision was in a low pressure zone. Waterman's have been upgraded, but I decided to stay with low pressure. Cylinder starting leaking after 22 years. Replaced 180 with 270 litre and pressure and tempering valves was close to 4000 dollars.
If going mains would have replaced shower mixer internals and some taps.

Went bigger for solar water heating diverted off PV, more storage.

No issues with low pressure, except perhaps takes a little longer for hot water to flow through to taps.

Oncop53

262 posts

Ultimate Geek

# 2271297 7-Jul-2019 13:00

One person supports this post

I had my low pressure one replaced with a mains pressure one for about $2K. Well worth the money, having mains pressure also gives you more options for tapware too.

hio77

'That VDSL Cat'
11488 posts

Uber Geek

Trusted

Spark

Subscriber

# 2271326 7-Jul-2019 15:12

One person supports this post

As a long term rural dweller, I've come to find low pressure as the norm.

When I stay anywhere the first thought in the shower is.. Sh1t that's quite rough...

While high pressure is nice every once in awhile. Idk how is stand that all the time!

#include <std_disclaimer>

Any comments made are personal opinion and do not reflect directly on the position my current or past employers may have.

1 | 2