Need more pressure.

Just moved home.

The central heating and hot water systems are gravity fed. The HW cylinder is in an upstairs airing cupboard above the stairs.The top of the cylinder is only 6-8" below the ceiling with the cold water header tank on a low platform in the roof space above. Even though the upstairs hot water feed is plumbed in 22mm the hot supply to the bath and sink is woefully slow flowing, this is not helped by the use of modern (no washer) taps which seem to slow the flow even more.

Can I install a pump in the airing cupboard in the 22mm coming from the top (output) of the HW cylinder? I only need to boost pressure for the hot water supply as the cold is at mains pressure and flows fine.

If so can anyone recommend a suitable pump? all I want to do is cut a length of pipe long enough for the pump to be fitted. I do have an electrical supply in the airing cupboard already.

Is this the correct way to boost hot water pressure rather than having to raise the cold water header tank in a gravity fed system?

Martyn

Reply to
Count de Monet
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Its the height of the cold water cistern that dictates the pressure, so the position of the cylinder does not have much bearing.

You really need taps designed for gravity fed systems to get adequate performance.

You can - although its often better to fit an Essex flange or Surrey flange to feed the pump - otherwise the more powerful pumps will just such air in via the vent pipe.

Stuart Turner do a 1.8 bar pump[1] that ought to give it a reasonable boost without causing too many implementation problems. You either need a single impeller pump, or to split the feed and combine the output on a dual one.

[1] I have used one of those from the top connection of a cylinder, and it worked ok without drawing air into the system.

Raising it helps - but only to a limited degree. Other options would be to switch to a unvented cylinder if you mains flow rate is ok.

Reply to
John Rumm

If you planning on staying put for a good many years I'd recommend getting a mains pressure hot water tank. Pumps can be noisy (unless very expensive) and have a limited lifespan. The sound of the pump kicking in when someone opens a hot tap at night is a potential annoyance.

Tim

Reply to
Tim

If there is enough height I would always raise the header/feed tank. Although more work there is nothing to go wrong once the installation is completed.

I live in a bungalow and have installed a shower which has pressure which is arguably better than that of a pumped shower in a nearby house. I built a tower for the header/feed tank in the loft. When full the surface of the cold water is about 6ft above the ceiling joists. The shower is fed from the hot tank with the cold feed coming from this header/feed tank, thus equalling the pressures.

Incidentally, I have modern (ceramic disk) mixer taps in the kitchen. The hot water flows through that tap just a well as it flows through any of the other traditional taps in the property.

Reply to
Old Codger

This is not to increase the flow to a shower, I can't stand for long due to a disability, I need to up the flow of the upstairs hot water so the bath fills without a long wait so a single impeller pump in the 22mm hot flow is all I need. I was hoping this was easier than a: taking out a perfectly good HW cylinder to replace with a mains pressure one or b: raising the cold tank in the loft. The pump solution seems, for me the easier DIY solution. The noise of the pump will only be heard when running and I can live with that.

Has anyone installed a single impeller pump and which manufacturer was preferred?

Reply to
Count de Monet

Stuart Turner pumps are quiet and reliable (but expensive). If you don't have a shower, you just need a single impeller pump but, as other posters said, you really want a Surry / Essex or similar flange on the tank which might be a PITA to fit on an old system.

You don't really want to feed a shower from a single impeller pump on the hot, and mains on the cold. It's probably breaking the water regs even with a non-return valve on the cold.

Reply to
newshound

As I said before, Stuart Turner are the Rolls Royce. They have a clever impeller (regenerative) which makes them quiet and powerful, and they are brass and seem to last forever (and you can get spares if they die). I was lucky enough to pick up a new one on eBay for about half list price.

BES lists a Grundfoss single impeller regenerative for only £112, but it is plastic rather than brass. I was getting about 5 years out of cheap power shower pumps before I moved to ST. BES also stocks several types of shower pump flange.

19507 SSR-1.5 C (1.5 bar outlet) regenerative mains shower pump
Reply to
newshound

Indeed....

Reply to
philipuk

Are you sure you are not confusing pressure with flow rate?

You need 30' of head for 1 bar of pressure. Even the most feeble shower pump will add at least 1 bar to the available pressure (assuming its working properly)

Reply to
John Rumm

They are related. Without adequate pressure you will not get adequate flow

I believe a more accurate figure is 34 feet.

pressure (assuming its

That is as maybe but I can assure you that the output of my shower is very acceptable and is arguably at a higher pressure (greater flow) than from a brand new pumped shower that I installed in a nearby house. I have experienced other pumped showers, not installed by me, and none had a noticeably higher output than my gravity fed shower.

Reply to
Old Codger

Performance, i.e. deliveruing hot water.

An avergae pumped gravity shower will outperform an average combi fed shower.

That rules out heatbanks then, which many seem to think are the mutts nutts.

We heat ours just before it's needed rather than just in case. If an emergency shower is required then it can always be taken cold.

It's horses for courses, but I will never fit a combi in a 4 bed detached with 5 people living in it. It just would not work.

MBQ

Reply to
Man at B&Q

That's why I was careful to compare average examples. There will always be outliers.

MBQ

Reply to
Man at B&Q

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Man at B&Q" saying something like:

Use two

Reply to
Grimly Curmudgeon

failure. If a pump fails in a combi - then that is a

The pump in my conventional Glow Worm is within the boiler casing. When it has failed in the past I regarded it as a pump failure.

Reply to
Graham.

failure. If a pump fails in a combi - then that is a

Wither way, its a system failure - and that is what actually counts.

Reply to
John Rumm

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