Hot water back on after 27 years but it's milky

[Jeff543]

Hot water back on after 27 years (now i have a boiler installed) but it's milky coloured. Do i let taps run and if so for how long? Is it likely not just air bubbles?

 

[JohnD]

Have you got a combi boiler?

Fill a glass with hot tapwater. Does it look milky?

Close your eyes for 30 seconds.

Open them again. Does it look milky?

 

[Jeff543]

Have you got a combi boiler?

Fill a glass with hot tapwater. Does it look milky?

Close your eyes for 30 seconds.

Open them again. Does it look milky?

It clears after a minute or so.

 

[JohnD]

Dissolved air.

Emerging at normal atmospheric pressure.

 

[Jeff543]

Dissolved air.

Emerging at normal atmospheric pressure.

So I can wash the dishes with it i.e. it's not poisonous? What's causing it? Faulty pipes?

 

[JohnD]

Air is not poisonous.

The water inside a combi is at mains pressure. Cold water, under pressure, can hold more dissolved air than the same water, either hot, or unpressurised, or both.

The water in the combi is heated up.

As soon as it emerges from the tap it is unpressurised and the excess dissolved air forces its way out.

Same as opening a can of coke

Or divers getting the bends.

 

[JonathanM]

Hot water back on after 27 years

I'm intrigued!

 

[mattylad]

At least you do not have a cow stuck in your boiler, this can be a problem that can give rise to milky water

 

[oilhead]

I've seen a 'professional' adjust the DHW inlet on a combi until it just starts turning milky and then declare it as at its optimum.