Hot water flow in loft bathroom

[rainbow100]

A few years ago I had a loft conversion with an extra bathroom. As the hot and cold tanks are both in the loft too, we get very poor water flow from the hot taps, but we thought we would switch to a combi boiler so we put up with it. When we eventually changed the boiler, we went for a non-combi (as there are 7 of us in the house).

I know that my sister-in-law had the same problem in her loft bathroom, and the plumber used a pump to pump water from the middle floor to the loft. However, whenever I've mentioned this to plumbers they've always said that a pump is not possible and I should have an unvented cylinder to serve the loft, which is much more expensive and more work to put it in.

Can anyone explain why a pump would not work?

Thanks for your help

 

[Prof.plumb]

I have not encountered a pump soley for the use of hot water. HOwever, obviously shower pumps do boost hot water, however they can use up to 12 litres a minute, thus you need a large tank and cylinder. If you do not have the space to accommodate these then yes the unvented method is probably better.

 

[rainbow100]

Thanks for your reply. Just to clarify - It's the sink and bath (especially the bath!) that are the problem since the shower is electric.

You mention a rate of 12 litres/min - what is the normal rate? Could a less powerful pump be installed?

One of my concerns about a megaflo ( which was suggested) is that it's rather heavy and can only be installed on the ground floor right at the back of the house, leaving a very long pipe run to the loft. This would mean loads of disruption throughout the house to route the pipes.

 

[bster]

Bronze pumps are solely for hot or cold water arnt they?

http://www.h-i-e.co.uk/acatalog/Bronze.html

 

[Nige F]

people are telling you a pump wouldn`t work because there wouldn`t be enough flow to activate the switches when you open a tap ..........but I`ve been looking @ techflow pumps from Techflow in Burgess Hill Sussex and they apparently have a automatic start neg head pump set that I`ve requested literature for via a branch of Plumb Center www.techflow.co.uk

 

[Softus]

Stuart Turner also do a range of negative head pumps; the quality is impressive.

 

[rainbow100]

Thanks for the explanation Nige F - I hadn't understood that a pump requires some pressure to work. I've had a look at the pumps everyone has suggested and I have a couple of questions:

What is an air switch? Does it mean that you would have to decide whether to turn the pump on or not?

Would the pump need to be fitted on the hot water pipes just before they split off for sink and bath?

Why do you think no plumber has suggested this solution so far? Are negative head pumps something new?

Thanks once again for your help.

 

[Nige F]

Air switch is so your hands don`t get near electricity ..and most neg. head setups need to be switched ON but turn off after use .........apparently this techno one is fully auto .....It`d better be cuz I `ve got one coming next week for my son`s flat So if it doesnt turn on+ off by itself and sense that the tap is open with a small flow of water ........I`ll want to know why, because I understand from techno`s technical dept. that it will do what I want

 

[rainbow100]

I'd be really interested to know if the pump performs as expected... would you mind posting your experience with it here? Then I can rehearse my speech for the plumber!

 

[Softus]

I've fitted many Stuart Turner negative head pumps - some single and some twin - and all perform as expected, i.e. they switch on automatically when a pressure drop is detected. They're expensive, but bloomin' marvellous.

 

[rainbow100]

But not as expensive as having a megaflo cylinder fitted two floors down?

 

[Nige F]

Be pleased to post an appraisal later........tho` I know Stuart Turners are the Rolls-Royce of pumps

 

[bab]

I take it the cold to bath & basin is on the mains so u only need to boost the not. stuart turner make single impeller boostamatic umps that give positive presure to the outlet side of the pump at all times & no need for the numatic air switch. the pump could also be fitted in the at the cylinder location if the hot feed was direct to the loft bathroom , If they have tee,d off the vent close to the tank u will have a problem with air being drawn in.

 

[rainbow100]

Yes, the cold feed for both is off the mains, so it would only be the hot that needs boosting.

I think the hot feed from the cylinder feeds the whole house so I presume there must be a diversion (is that what tee'd off means?) somewhere. Why would there be a problem with air being drawn in?

Please excuse my ignorance - I'd rather be lying in the bath with a glass of wine than thinking about how the hot water got there!

 

[Nige F]

Shouldn`t be a problem with air if an Essex flange is fitted to the side of the cylinder to feed the pump.....I`d go with this setup and the Stuart Turner pump in your case.....and if within travelling distance of Sussex .......I`d get me in to fit it