Capping hot water pipe

[Darran]

Hi
My current bathroom hot water piping enters the bathroom on a T joint, with one pipe going right angles to the sink and the other going straight on to the bath. I'm moving the bath towards the sink, and am able to run the bath off the same pipe as the sink. I was just going to cap the remaining pipe, but wondered whether this could cause stagnant water. The nearest place to cap it with relative ease is 1.3m from the T-joint. Is it okay to cap it there, or must I cap it a smaller distance from the T, or replace T-joint with an elbow?

 

[Softus]

Capping it in the place most convenient to you is not a problem.

Stagnant water? Not really very likely. Either the water will be truly stagnant, which means it will never mix with the fresher water, or, if it does mix, then it won't be stagnant, QED.

Having said that, perhaps I'd generally avoid dead-end pipe runs on the cold mains supply...

 

[ChrisR]

Call me paranoid, but stagnant hot water, no thanks. Legionnaires & Pontiac.

This is typical bumph:>>>

Where do Legionella bacteria come from?

The Legionella bacteria are found naturally in the environment, usually in water. The bacteria grow best in warm water, like the kind found in hot tubs, cooling towers, hot water tanks, plumbing systems, or parts of the air-conditioning systems of large buildings.

How do people get Legionnaires’ disease?

People get Legionnaires' disease when they breathe in a mist or vapor (small droplets of water in the air) that has been contaminated with the bacteria. One example might be from breathing in the steam from a whirlpool spa that has not been properly cleaned and disinfected.

... outbreaks have been linked to aerosol sources in the community, or with cruise ships and hotels, with the most likely sources being whirlpool spas, cooling towers (air-conditioning units from large buildings), and water used for drinking and bathing.

Death results in up to 5% to 30% of cases.
<<<
WHat the hell is "up to 5% to 30%" supposed to mean!!

 

[Softus]

Chris, IMHO you're midly paranoid, but that doesn't mean that the risk is nil

I'm not a fan of posting links to random web sites, but the following article is interesting and has the air of scientific authority about it:

Legionella in hot water systems

To correct my earlier statement, the only entirely risk-free course of action is to remove the dead leg of pipework, i.e. to change the tee for an elbow.