Cold water out of hot water tap?

[digisatman1]

Hey all,

I have a mynute 20se condesning boiler with a Santon Premier TP 150b unvented tank.The only problem I have is with the water out of hot taps - the central heating etc is fine.

I have a problem with water coming out of the hot water taps, it seems that when I turn it on, it always tends to come out cold for a few seconds before turning to normal hot. It never used to be like this - this problem only started happening since last week.

For example, in the shower, when i turn it on cold water comes out for a few seconds, then goes to normal warm, if i turn it off mid way then on again, cold water comes out again for a few seconds then returns to normal. It seems like hot water is not remaining in the pipes?

I asked a friend, and they told me that this symtomn is normal(something to do with the expansion tank) however it shouldnt be happening reguarly as it is.

Any ideas?[/b]

 

[Nige F]

There must be cold water creeping past a non return valve from cold to hot As I`m not Gas or Unvented certified , I can`t offer any more advice - I have been certified in other ways though

 

[sooey]

I can't see the problem, it's normal to wait a few seconds for hot water to get to the taps.
The shower sounds ok too, if it's a thermostatic mixer you'd expect it to start off cold and adjust itself up to temperature.
Why would you want to turn it off halfway through and restart it anyway?

 

[craig51]

DOes this boiler have an ECO mode or a preheat function??? If it does, see if its been turned off.

 

[HootingOwl]

....it isn't a combi

there may be a secondary circulation pump on the how water circuit from the unvented. that may have been turned off.

 

[craig51]

My bad, your right.

QAs above, check secondary circulating pump is one (and working!!!)

 

[digisatman1]

Hi all,

As far as im aware, nothing has been changed/switched off...How do i check the secondary ciculating pump? Heres some pics of the tank upstairs that I have.

Thanks for the replies.

 

[HERTS P&D]

What's holding the expansion vessel?

Andy

 

[DP]

Is the cold to the shower taken after the pressure reducing valve or before?

Can be an issue if the hot and cold feeds are not balanced

Messy work on the fittings

 

[sooey]

Messy work on the fittings

They're yorkshires as well....there's nothing like making sure.