Water pressure low upstairs

[Marnhullman]

I have a 3 1/2 year old house with a sealed system and pumped hot water. The pump is connected to the central heating timer so only operates when the hot water is being heated. We therefore have pumped hot water first thing in the morning and in the evening.

The incoming mains pressure is okay but the pressure upstairs is not. When either hot or cold taps are opened there's an initial spurt but then the flow slows significantly. My neighbour's water pressure is fine on both floors.

I have cleaned and de-scaled the tap filters and I can't find a pressure valve near the stop cock, which I believe is not a requirement if the incoming pressure is not more than 3 psi?, although I would have expected there to be a valve in an otherwise high spec new build house?

Could the low pressure be caused by the DHW pump not functioning as it should? Bear in mind the pressure doesn't seem to change whether the pump is operating or not. The pump does work because hot water comes out of the tap instantly when its on but there is a flow of cold water initially before the hot water flows when the pump isn't running.

Could there be a blockage in the pump?

Any thoughts appreciated.

 

[HERTS P&D]

Post a picture of any pumps you have.

Andy

 

[Marnhullman]

It's a Glow Worm Energy 18s boiler with the first pump. The DAB pump is in the airing cupboard adjacent to the hot water cylinder.

 

[CountryFan]

Both of those are heating pumps. What hot water cylinder do you have?

 

[Marnhullman]

 

[CountryFan]

View attachment 420559View attachment 420560

Ok. So you have an unvented cylinder, which works off the incoming cold main. There are a couple of reasons why the “pressure” may be low, but only one you can check as DIY - make sure the stopcock is fully open. Everything else needs a G3 registered engineer.

 

[Marnhullman]

Thanks for your advice.

Regards

 

[dilalio]

Have you noticed a drop in pressure/flow at the kitchen cold tap recently?

It's fairly likely that water authorities have been reducing network supplies due to the drought conditions recently.

As someone joked to me yesterday...
"anyone who's disposed of a body in a reservoir must be very nervous right now!"

 

[Marnhullman]

Ha, ha! No, the pressure from the rising main is okay. I've ordered a gauge to check the actual pressure but did a test by filling a 1 litre jug and timing how long it took to fill it. Downstairs took 6 seconds, upstairs took 13 seconds.

Bizarre.

 

[Lower]

Ha, ha! No, the pressure from the rising main is okay. I've ordered a gauge to check the actual pressure but did a test by filling a 1 litre jug and timing how long it took to fill it. Downstairs took 6 seconds, upstairs took 13 seconds.

Bizarre.

Not really. The static pressure will be the same upstairs and downstairs, but the dynamic pressure will be lower upstairs as some of that pressure is being used to push the water flow up against gravity,

 

[DP]

Ha, ha! No, the pressure from the rising main is okay. I've ordered a gauge to check the actual pressure but did a test by filling a 1 litre jug and timing how long it took to fill it. Downstairs took 6 seconds, upstairs took 13 seconds.

Bizarre.

Initial high flow may be attributed to mains pressure pressurising the expansion vessel to static mains pressure when no hot water is drawn.
When a hot tap is run, you get combined pressure from pressure ‘stored’ in the vessel and the main cold pressure until the vessel pressure drops to the pressure exerted by the air side

Do you have hard water? If so wonder if restriction could be furring the pipes to upstairs taps.

Bronze pumps were at times used to minimise wait time for water to reach remote hot taps. Now these pumps are sometimes made from collection of material that do not rust and may not be easily recognisable

The drop in flow between upstairs and downstairs is significant.
Take it you have checked the flow from all the hot taps upstairs

 

[Marnhullman]

I managed to speak to the plumber who installed the system, this morning, and he has no suggestions. He did mention that the hot and cold feeds to the taps are balanced to prevent sudden changes of temperature in the showers. It wasn't clear to me how that was achieved so maybe that has an effect?

The flow to all the hot taps upstairs is low.

 

[CountryFan]

I managed to speak to the plumber who installed the system, this morning, and he has no suggestions.

Wow! Maybe he just installs them then?

He did mention that the hot and cold feeds to the taps are balanced to prevent sudden changes of temperature in the showers. It wasn't clear to me how that was achieved so maybe that has an effect?

The pressures are generally the same, therefore balanced

The flow to all the hot taps upstairs is low.

Maybe try Joule?