what boiler system if low mains water pressure

[Roger928]

Ok, just had a boiler guy round earlier to test water pressure and flow.

The results are in....

....drum roll please....

....6 bar pressure and 24lpm water flow.

So looks like mains upgrade not required.

At 6 bar static its unlikely you won't be achieving 20l /min @ 1 bar dynamic. I have 7 bar static in my home and 20l /min @1.2 bar dynamic.
All piped in 15mm copper.
Static pressure is not irrelevant when its high pressure. Unless the property had seriously convoluted pipe runs or blockages.

I did my brothers loft conversion a few years ago. Just ran a 15mm mains supply and electric shower and ariston water heater for the basin. Job done.
Changing it over to an unvented cylinder would have been at least 3 times the cost. And you have the issue of the old pipework not withstanding the pressure, an installation nightmare with the discharge pipe plus a yearly service.
It also ruled out the need for a secondary return circuit as it was a long run.


I've heard of a unit that bolts to the side of the cylinder which incorporates a plate heat exchanger and uses the energy in the existing vented cylinder to provide mains hot water to the taps.
I've never seen any merchant stock it though or seen one in action.
Availability issues will probably make it prohibitively expensive.

 

[MikeJEN]

Ok, just had a boiler guy round earlier to test water pressure and flow.

The results are in....

....drum roll please....

....6 bar pressure and 24lpm water flow.

So looks like mains upgrade not required.

At 6 bar static its unlikely you won't be achieving 20l /min @ 1 bar dynamic. I have 7 bar static in my home and 20l /min @1.2 bar dynamic.
All piped in 15mm copper.
Static pressure is not irrelevant when its high pressure. Unless the property had seriously convoluted pipe runs or blockages.

I did my brothers loft conversion a few years ago. Just ran a 15mm mains supply and electric shower and ariston water heater for the basin. Job done.
Changing it over to an unvented cylinder would have been at least 3 times the cost. And you have the issue of the old pipework not withstanding the pressure, an installation nightmare with the discharge pipe plus a yearly service.
It also ruled out the need for a secondary return circuit as it was a long run.


I've heard of a unit that bolts to the side of the cylinder which incorporates a plate heat exchanger and uses the energy in the existing vented cylinder to provide mains hot water to the taps.
I've never seen any merchant stock it though or seen one in action.
Availability issues will probably make it prohibitively expensive.

I know electric shower would be easier but not keen as they don't exactly look great and aren't they expensive to run?

How did you get central heating in your brothers loft?

 

[PullerGas]

There's a common misconception running through this thread; pressure & flow are not the same thing.

 

[PullerGas]

Bennygreen is the forum troll.

I (Bernard Green) have designed and installed the heating and hot water systems in the house I ( with my wife ) self built ( total DIY ) in 1981 and in the Grade II listed cottage that I am living in now. They work and provided all that was needed and some of the "unconventional" design features have been used by qualified heating engineers in other projects.

PullerGas installs systems as a means of earning a living. He doesn;t have to live in the houses after the install is completed. He is qualified and at times uses this to "prove" his opinion is correct and that he is also Qwallified to denigrate anyone who has a different opinion to his.

Sorry to turn this into a fight of words but PullerGas was the first to be unpleasant.

This made me laugh, heartily!!
BG you're a Google Warrior & troll.
You wax lyrical & write drivel.

 

[Roger928]

His central heating was tapped into the existing system. I did make a mistake on it thinking 15mm would work on a section through a nasty convoluted pipe run under the floor boards and later had to rectify it using 22mm.
But I resorted to 22mm MLC which threaded in like soft drawn copper.

 

[MikeJEN]

His central heating was tapped into the existing system. I did make a mistake on it thinking 15mm would work on a section through a nasty convoluted pipe run under the floor boards and later had to rectify it using 22mm.
But I resorted to 22mm MLC which threaded in like soft drawn copper.

So cold water tank in eaves and F&E tank high up to a position in height above the rads?

 

[Agile]

I fully understand the need to test dynamic pressure and flow if I want an unvented system.

I've done the pressure and will do flow later.

.

But you dont seem to have understood.

The whole point of measuring the dynamic flow rate is to measure them together at the same time!

You could keep your house as it is and just run a 15 mm cold to the loft and have an electric shower and electric under sink heater for the basin.

Electric showers cost about the same per minute of use as gas heated showers.

Tony

 

[bernardgreen]

This made me laugh, heartily!!
BG you're a Google Warrior & troll.
You wax lyrical & write drivel.

And I have a working system......

You, Sir Richard Puller, have an ego problem

 

[Steelmasons]

Non-vented cylinders were introduced for use in flats and situations where a loft tank was not possible

Really???

Provided the pump is below the cylinder then gravity will ensure that there will be water in the pump when it is started ( if the pump is above the cylinder then the pump may have pump air to suck water up to it before it can start pumping water.

The pump wont start should air be entrained within flow switch.

The only addition I would make is a level sensor in the cold water loft tank to shut off the pump(s) if they are drawing water faster than the mains can refill the tank and the tank is close to being empty.

....these domestic type pumps will automatically shut off when starved of water..
Advising the use of level sensors when referring to domestic?????

 

[bernardgreen]

Advising the use of level sensors when referring to domestic?????

Advising the installation of a pressure vessel that requires annual checks on its safety devices instead of vesseal that is vented and thus does not need safety devices. ?????

 

[Steelmasons]

I haven't advised anything.

 

[Steelmasons]

instead of vesseal that is vented and thus does not need safety devices. ?????

Does a vented vessel actually exist?

 

[PullerGas]

This made me laugh, heartily!!
BG you're a Google Warrior & troll.
You wax lyrical & write drivel.

And I have a working system......

You, Sir Richard Puller, have an ego problem

The general concensis is that you're an rsole BG.

I don't have an ego problem son, I just say it as it is. I've the training, experience & skill. While you're a Google Warrior.

 

[ianmcd]

OP you will not be happy until someone says that the cheapest way to do it is the best so why ask for advice that you dont want to hear , just go with your cheap option and convince yourself that it is great

 

[MikeJEN]

OP you will not be happy until someone says that the cheapest way to do it is the best so why ask for advice that you dont want to hear , just go with your cheap option and convince yourself that it is great

Ok ianmcd...wasn't sure what to do but after your post all is clear. Thanks for your useful input.

I actually do want to hear all advice, opinions and views...that is the reason why I asked the question. I've got a healthy budget so isn't necessarily solely down to cost.