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?
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[glenno1]

This sounds normal because hot water has to travel from source to taps,which takes a few seconds

 

[Simon F]

Hello digisatman,
It does sound normal, but you are saying that this is a change yes?
how long have you been at the property?

do you have a secondary return pump that is not working?
is the shower fed from the hot water cylinder or is it electric?
is there a thermostatic mixer somewhere that is faulty?
how long is the turn of period for the water to run cold to the shower?

more specific details may help

 

[lbp plg & htg]

Is there a picture of the pipework around the combination valve available?

 

[digisatman1]

Hello digisatman,
It does sound normal, but you are saying that this is a change yes?
how long have you been at the property?

do you have a secondary return pump that is not working?
is the shower fed from the hot water cylinder or is it electric?
is there a thermostatic mixer somewhere that is faulty?
how long is the turn of period for the water to run cold to the shower?

more specific details may help

Hi all,


As far as im aware, nothing has been changed/switched off...it didnt use to do this a few weeks ago, its only started occuring now and Ive lived at this property for over 10 years! Im not sure about if the secondary return pump is working - not sure how to check?

Shower is fed from hot water cylinder, but the thing is that the problem also occurs in the taps around the house.

For the water to run cold to the shower when turn off, its instant, as in if i switch shower off mid-shower then turn on ice-cold water comes out for about 5 seconds - definitely didnt used to do this either!

Heres some pics of the tank upstairs that I have.

Thanks for the replies.

 

[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.

 

[Jamie Plumbteq]

Hi if you have looked into simons suggestions also keep in mind if your on the ground floor it could be a leak you arent seeing, I had 2 problems similar last year.

Regards Jamie

 

[Megaflo-Experts]

Does not sound right!
If you turn the shower off mid way, and then back on again, the hot should still be hot.
Does this happen with all hot taps?

As already asked, do you have secondary hot water?

 

[stevetheplumber]

sounds like a nonreturn problem some where have you changed any taps recently