Horne Engineering Ltd
Issue 3 8/05
3
3 COMMISSIONING A NEW HORNE 25 TMV
3.1
Open the hot water tap and allow water to run through the Horne 25 TMV.
3.2 Check that the hot and cold water supplies are at or near their designated
temperatures and pressures.
3.3 Measure the temperature at the hot water tap. This is the temperature of the mixed
water.
3.4 If necessary, make minor adjustments to the temperature setting as described in
Section 4 below.
3.5 CARRY OUT A COLD WATER FAILURE TEST AS BELOW
3.5.1 Close the cold water isolating valve and simultaneously measure the mixed water
temperature. The flow of mixed water should immediately stop and then a drip or
trickle may be seen. The temperature of any water coming from the tap should not
be more than 2C above the mixed water temperature measured in 3.3 above.
3.5.2 If the Horne 25 TMV performs satisfactorily, close the hot water tap and open the
cold water isolating valve.
3.5.3 If the water coming from the tap is at a temperature of more than 2C above the
mixed water temperature setting, then the Horne 25 TMV is not cutting off the hot
water supply properly. The most likely cause for this to happen is dirt inside the
TMV. It should be dismantled and thoroughly cleaned and the pipework flushed
again. See 2.5 - 2.16.
3.6 The Horne 25 TMV is supplied with WFBS listed integral single check valves
located in each of the inlet couplings. To ensure the check valves are working
properly, proceed as follows :-
3.6.1 Start with both hot and cold taps closed and both hot and cold water isolating
valves open.
3.6.2 Close the cold water supply isolating valve.
3.6.3 Remove the cold water inlet STRAINER CAP (16) at the inlet to the Horne 25
TMV. After initial draining of water, there should be no flow whatsoever. This
indicates that the check valve at the cold water inlet is giving a tight shut-off.
3.6.4 Replace the cold water inlet STRAINER CAP (16) and open the cold water
isolating valve.
3.6.5
Close the hot water supply isolating valve.
