Boiler / Hot Water Pressure advice needed

southcoastrgi

The 3 bar pressure did he measure it with a tap running ?

fezster

I've found measuring flow from just a single tap doesn't give an accurate reading. You need to run multiple taps and add the flows together, whilst using a third outlet to measure the dynamic pressure.

If you have good pressure at any time of day, a non pumped accumulator can be sized to ensure your water requirement is always met and boost both your flow and dynamic pressure. However, the tanks are huge and only provide approx 50% capacity, as the other half is full of air. 

DettaWalker

southcoastrgi said:

The 3 bar pressure did he measure it with a tap running ?

no he just measured it from the outside tap. but next week we will have a a G3 certified person coming to do a site survey

Jeepers_Creepers

Please keep us updated with this project, Detta, as there are regular posts about such issues. :-) 

southcoastrgi

DettaWalker said:

southcoastrgi said:

The 3 bar pressure did he measure it with a tap running ?

no he just measured it from the outside tap. but next week we will have a a G3 certified person coming to do a site survey

That's standing pressure which means very little you need working pressure, measure the os tap with the kitchen tap running 

DettaWalker

so, we had the G3 guy around, he did a test for pressure which was near 4 bar on the outside tap, then 3 bar on the outside tap with the kitchen tap fully open.
He also measured flow of 20l/m
He's now recommending a standard unvented cylinder to replace our vented cylinder and cold water tanks in the attic.
I'm awaiting the details of the unvented cylinder, but my personal preference would be an in-direct unvented cylinder with a backup immersion heater should our boiler fail. Any opinions on this?

I've also just received a quote (without the breakdown, that is yet to come) for:
1 unvented cylinder, slimline, 210 litres to go in the airing cupboard as the loft opening won't fit a loft unit.
Removing the old cylinder and cold water tanks, replacing the mains water feed from a 15mm pipe to a 22mm pipe (he has to feed it up to the attic, over the bathroom and down the existing pipe rack into the kitchen)
Fitting the new cylinder and replacing the pumped shower unit (new unit not included) from the existing aqualisa digital shower with one suited for unvented cylinders.
All in all this is to come to roughly £2100 with an estimated 2 days of labour.
Does this quote sound reasonable? We live in Reading..near London so I expect us to be more expensive than up north.

Jeepers_Creepers

DettaWalker said:

so, we had the G3 guy around, he did a test for pressure which was near 4 bar on the outside tap, then 3 bar on the outside tap with the kitchen tap fully open.
He also measured flow of 20l/m
He's now recommending a standard unvented cylinder to replace our vented cylinder and cold water tanks in the attic.
I'm awaiting the details of the unvented cylinder, but my personal preference would be an in-direct unvented cylinder with a backup immersion heater should our boiler fail. Any opinions on this?

I've also just received a quote (without the breakdown, that is yet to come) for:
1 unvented cylinder, slimline, 210 litres to go in the airing cupboard as the loft opening won't fit a loft unit.
Removing the old cylinder and cold water tanks, replacing the mains water feed from a 15mm pipe to a 22mm pipe (he has to feed it up to the attic, over the bathroom and down the existing pipe rack into the kitchen)
Fitting the new cylinder and replacing the pumped shower unit (new unit not included) from the existing aqualisa digital shower with one suited for unvented cylinders.
All in all this is to come to roughly £2100 with an estimated 2 days of labour.
Does this quote sound reasonable? We live in Reading..near London so I expect us to be more expensive than up north.

Cool - sounds like good figures. And if he replaces the cold feed with 22mm, that should help further.

Yes, it would be 'indirect' - you wouldn't have any option there! 'Indirect' means that the boiler, rads and the heating coil in the cylinder share the same sealed water. 'Direct' hasn't been used for decades...

DettaWalker

Jeepers_Creepers said:

DettaWalker said:

so, we had the G3 guy around, he did a test for pressure which was near 4 bar on the outside tap, then 3 bar on the outside tap with the kitchen tap fully open.
He also measured flow of 20l/m
He's now recommending a standard unvented cylinder to replace our vented cylinder and cold water tanks in the attic.
I'm awaiting the details of the unvented cylinder, but my personal preference would be an in-direct unvented cylinder with a backup immersion heater should our boiler fail. Any opinions on this?

I've also just received a quote (without the breakdown, that is yet to come) for:
1 unvented cylinder, slimline, 210 litres to go in the airing cupboard as the loft opening won't fit a loft unit.
Removing the old cylinder and cold water tanks, replacing the mains water feed from a 15mm pipe to a 22mm pipe (he has to feed it up to the attic, over the bathroom and down the existing pipe rack into the kitchen)
Fitting the new cylinder and replacing the pumped shower unit (new unit not included) from the existing aqualisa digital shower with one suited for unvented cylinders.
All in all this is to come to roughly £2100 with an estimated 2 days of labour.
Does this quote sound reasonable? We live in Reading..near London so I expect us to be more expensive than up north.

Cool - sounds like good figures. And if he replaces the cold feed with 22mm, that should help further.

Yes, it would be 'indirect' - you wouldn't have any option there! 'Indirect' means that the boiler, rads and the heating coil in the cylinder share the same sealed water. 'Direct' hasn't been used for decades...

Makes sense. 
Little update here, the unvented cylinder was just fitted - the water pressure is amazing, so much that we are spraying our faces with water in certain sinks, but you're working on that today.. The only thing now is that my boiler isn't coming up to temperature anymore and the radiators are not getting hot anymore - warm but not hot - and with the current weather of -1 outside, this doesn't manage to heat up the house to anything above 16c.
They'll investigate once they're done with running the new pipe but that is worrying. I wonder if my boiler has enough capacity to deal with the new cylinder whilst also heating the house. It's set to 74 degrees but only gets up to 62 and the radiators are just .. meh.. 

Will update again

Jeepers_Creepers

Your boiler shouldn't struggle - it's no more difficult to heat this tank than the old one.

You should have full control over it, tho', so surely you can turn off the DHW and see if the rads then heat up properly? Anyhoo, the guys are on it...

Let us know :-)