Frothy hot water!

[herbert13]

Since the last 2 days my hot water comes out of the tap like shaving foam!
The cold water is unaffected.
My hot water system is a sealed pressurised system (3 Bar) with a 500 litre (yes 500 litre!) dual coil hot water tank (1 coil for condensing gas boiler and the other to a solar panel).
Approx 2 weeks ago I drained the tank to replace an immersion heater that was causing a leak. This was successful at curing the leak but 2 days ago the foaming started.
The hot water pressure is unaffected and the foaming settles after approx 5 seconds if the hot water is poured into a glass.
I would appreciate advice on what could cause this problem

Many thanks

 

[Agile]

You did not say the make of cylinder.

I am guessing that its one with an integral air bubble to absorb expansion?

If so then perhaps the more soluble oxygen is dissolving in the water.

If I am right then it will diminish in a few days as the oxygen is used up.

I also wonder if the cylinder pressure might be too high for some reason?

Tony

 

[herbert13]

The cylinder is a Yorktank.
The hot water feels very soft and is the consistency of shaving foam almost until it settles into clear water
I am wondering if the Kinetico water softener that is attached to the system may be to blame- the hot water has a "metallic" smell?
The water softener is 5 years old

 

[JohnD]

I have a feeling it may be the corrosion inhibitor getting into the cylinder, e.g. from a split coil.

As you have a sealed system I would expect that to change the pressure reading, but am not familiar with your design.

 

[oilman]

..............the foaming settles after approx 5 seconds if the hot water is poured into a glass.
..............

It is NOT like shaving foam then. Please be accurate and not dramatic with your descriptions. We could help, but not if we get poor information.

 

[herbert13]

There are no changes in pressure on the gas boiler hence a split coil is probably unlikely.
The tank is stainless steel and constructed to industrial standards- I would have thought the coils should last longer than 5 years in a domestic situation.
I have bypassed the water softener this weekend and the foaming has diminished but is still present on the hot water only.
Maybe when we have got through the 500 litres of softened water in the tank we will have an idea if the softener is at fault

 

[doitall]

Water softener almost certainly the problem. have you let it run out of salt and the thing is/was filled with water.

 

[herbert13]

Thanks for your concern, "Doitall"!
The softener is totally bypassed at present so no water running through at all.
I contacted the guy who fitted the softener (approx 5 years ago) and he had no explanation for the foaming.
What do you think is wrong with the softener?
Is it worth a total replacement or do you think a repair will do the trick?
I have heard these Kinetico softeners use a lot of water and can be unreliable

 

[doitall]

kinetico are one of the best.

They dont like running out of salt, and you have to reset everything, best to get their service guy to service it.

Have you tested the hardness of the water with your tablets and what is the reading.

 

[herbert13]

I am fastidious about keeping the softener up-to-date with salt and it has never run out.
I have had no complaints re. the water softness, just this foaming that started recently.
It may not be the Kinetico that is causing the problem- I just cannot think what else it could be?

 

[doitall]

More info about the rest of the system.

Is the storage tank Fibre glass, if so have you checked inside for contamination, is there a pump set involved.

 

[herbert13]

It is a 500 litre Yorktank, stainless steel with 2 coils- 1 to the gas condensing boiler (running 1 Bar pressure) and a solar coil to a solar panel (running at 1.5 Bar)
The tank is mains pressurisedand limited to 3 Bar
The whole central heating and hot water system is 5 years old.
There are no pumps as it is a pressurised system