Flow rate too high on boiling water tap.

[ProDave]

We have a boiling water tap, sold under the brand name Lamona by howdens, it is in fact a ProBoil 2

 

It's about 6 years old.  Up until a week ago when you turned on the boiling water tap full, it dispensed it's boiling water at a nice steady slow flow rate that would gently fill your cup with hot water.

 

Came back yesterday from a week away, and now the boiling water comes out way too fast, to the point of being dangerous, the only way to use it is just crack the boiling tap open a tiny amount.

 

There is no mention in the manual about adjusting the boiling water flow rate, and no visible obvious adjustment, and searching has hailed to find anyone discussing the same problem, so I am asking the forum for advice please.

 

This particular boiling water tap is not really boiling but 98 degrees.  the way it works is the "boiling tap" on the tap unit turns on the cold water feed into the boiler, and the hot out from the boiler goes straight to the tap with no valves (it acts as the vent) So cold water going in pushes boiling water out.

 

Picture:

 

 

The thin blue hose is the cold water from the tap into the boiler, and the clear hose with a red nut is the boiling water out to the tap.  All fittings are those supplied with the unit.

 

If the brass fitting on the cold in pipe is the restrictor, there are no adjustments on it, but I guess that might be a good place to start looking?

[dpmiller]

yep look in the brass fitting. bit of grit under the rubber disc maybe

[ProDave]

Brass fitting removed and it is nothing special, just a thread adaptor with a hole straight through it.

 

So it looks like continue the search for the real flow restrictor, or contrive one myself?

[dpmiller]

Dave the manual refers to  a check valve being in/under the blue inlet fitting, try there...

[ProDave]

Yes there is indeed a non return valve inside the blue inlet fitting.  It was a bit fiddly withdrawing it for a look, and having removed it I could see nothing wrong.  It was functioning as a non return valve and had no obvious mechanism that would make it a flow restricting valve.

 

So I have put it all back together awaiting further inspiration, turned the water back on and tried it, and everything is back to normal with the correct nice and gentle flow rate of boiling water.

 

So it is "fixed" without having the faintest idea what was wrong.  That does annoy me intensely.