Re: vaillant combi and pressure

[Ed Sirett]

> Hi a few months ago i noticed a very small leak from one of the pipes > underneath the boiler.I just put a pot to catch water because it seemed > so small,after a few weeks it stopped.Now couple of months later noticed > pressure gauge was low i dont know if its connected to the leak or not.I > used loop to top up water today and it seems fine no leak.The weird > thing is for the last few days the boiler turns itself on like somebody > was using hot water or having a shower.It only lasts a few seconds every > few hours then u can hear it turn the gas back off, i live on my own so > it cant be anybody else and no taps been left on any idea why its > turning on?

The leak could well account for the loss of pressure. See Sealed-CH FAQ. It is possible that you have changed a switch or setting between cold and warm standby modes. In the latter the boiler will fire for a few seconds every so often.

Which model is it?

[andrewpreece]

I believe that one can tell whether it is in standby hot-water mode by looking at the green led: I think it flashes on and off? Not sure. At any rate, the way to turn that mode off is to turn the DHW knob all the way to low tempertature then back to the desired temperature.

Andy.

[Ed Sirett]

This will depend on the model. On Eco/Turbomax+s the green light is on steadily in warm standby, but blinks when the DHW or Preheat is in action. It's off when in cold standby.

On Sines there is a rocker switch with some Euroglyphics [1] the solid rectangle means warm and the triangle mean cold standby. Given that the boiler has leaked the chances are that this is an older model.

HTH

[1] My term for any symbol whose etymology is variable, arcane and probably less helpful than a foreign word or two. Whilst, say, the Hare & Tortoise is clear. Nevetheless, a simplified picture of a face with a top hat going up a ladder is less than obvious that this means "burner test".