Tap Problem

[help]

Help needed, I am renting a unit and have broken the spout of the tap, bought new tap (basin mixer tap), removed old tap and there is 3 x 10mm flexi pipes hot, cold and other, what is other for, there is a heater box in corner if this helps, explained this to local plumbing shop and no help.
new tap has 2 x flexi pipes in box and 2 x holes (hot,cold)
I need to get this sorted before landlord bills me to get plumber in ( he uses big companies wont be cheep)
What is this tap and where can I get one?
Help!!!!!!!

 

[macplumb]

Could you post a photo? Do all flexis come out of tap? Could be on a blending valve.

 

[Puddle]

think maybe the third pipe is the expansion pipe for the electric heater if it over heats,there is a pressure release valve built in tap
Therefore tap is a special tap for heater unit and the tap you have is no good
You should not work on this as requires pipeing up correctly or could be dangerous,you have been unlucky and will need to get someone in

 

[stevetheplumber]

think maybe the third pipe is the expansion pipe for the electric heater if it over heats,there is a pressure release valve built in tap
Therefore tap is a special tap for heater unit and the tap you have is no good
You should not work on this as requires pipeing up correctly or could be dangerous,you have been unlucky and will need to get someone in

thats right puddle the water goes into the tap thru the valve and back to the water heater then out again thro tap spout
the tap you have is no good go back to the merchants and get a tap for the heater you have fitted it wont be cheap but cheaper than paying a plumber for two visits cos he wont have one of these on board