Hi wonder if you can help me, I am recently retired building services engineer so have meters and can test electrics, water pressures, etc., on this shower. My father has a Topaz 100i and I have been through the forum and checked through all the similar problems but still have a problem and would appreciate any help as we are stumped.
Their shower keeps going cold like many I read about on this forum and auto reset and low pressure come on intermittently followed by cold water. Auto reset goes off fairly quickly but low pressure sometimes stays on keeping water cold and won’t go off without turning unit off and on to get it back to normal working
This is where I am at, I tested the house for pressure and was surprised to find my father has 5.5 bar water supply to his house, so quite strong compared to many I tested before. I then tested right behind the shower water inlet to prove this pressure is getting there and there are no restrictions/valves etc. I found the same pressure here. I then tested with kitchen (mains fed ) tap full on and it dropped to 2 bar although they never have it open full normally and not at all now because shower is playing up, but 2 bar is quite adequate anyway even if they did.
So plenty of pressure, I then tested electrically. Looking at this diagram
http://showerdoc.co.uk/shower-spares/triton/topaz-t100i-electric.html
I metered across thermal cut-out on top of the heater can assembly and found 240v both sides i.e. looks like switch is normally made during operation. I then metered across the switch on the outlet pipe assembly which says it is also a TCO in the shower manual and this gave 24v whilst in use on both sides so looks normally made during operation also. What I am really curious about is how this unit can bring up a low pressure warning light when the only sensors I can find are the 2 TCO (thermal cut-outs), it makes me doubt the bottom one is a thermal cut-out and is maybe is in fact a pressure sensor. But it refers to this as a TCO several times in the manual so how is it detecting pressure, where is this mystery sensor?
I have played with the stabiliser valve with the cover off, i.e. I have found it goes much further than the dial on the front cover will allow before hitting its true stops. By doing this I managed to get a really powerful shower going, only trouble is the heaters could not cope and cold water came out even though the both heater relays were energised thus energising the elements, and therefore trying to heat the water. You may ask why I messed about with this, well the reason I altered it was because I found that the low pressure light extinguished doing this as if the pressure coming out of the outlet was too low in pressure and that was causing the problem. Next to try and get optimum performance from the shower I started turning it so it gave maximum pressure but cold water and then slowly turned it down to decrease the water pressure coming out of the hose until it was producing hot water, thus giving me hot water at the best pressure this shower can manage. By then turning the dial on the cover to maximum and fitting the cover back, it was set to give that pressure at that temperature at maximum.
By doing this I thought I had cracked the problem as it seemed to be working the best it could with no faults, but I then turned it down with the cover on as per normal use to 9, the setting my father uses and in seconds the low pressure light lit and the water went cold and would not stabilise. I had to turn it off and on again to get it working. But now as before i touched it, it brings up low pressure whenever it is turned to 9 or below, so I have actually achieved nothing.
My guess is that the outlet assembly contains a pressure switch and not a TCO otherwise how does it detect pressure is low? If I am right this needs replacing as the shower water comes out with reasonable pressure although nowhere near 5 bar I reckon, which is a great pity as I have proved you can get a load of pressure out but only if you like it cold.
Anyway I would appreciate any help as I am stuck now.
Their shower keeps going cold like many I read about on this forum and auto reset and low pressure come on intermittently followed by cold water. Auto reset goes off fairly quickly but low pressure sometimes stays on keeping water cold and won’t go off without turning unit off and on to get it back to normal working
This is where I am at, I tested the house for pressure and was surprised to find my father has 5.5 bar water supply to his house, so quite strong compared to many I tested before. I then tested right behind the shower water inlet to prove this pressure is getting there and there are no restrictions/valves etc. I found the same pressure here. I then tested with kitchen (mains fed ) tap full on and it dropped to 2 bar although they never have it open full normally and not at all now because shower is playing up, but 2 bar is quite adequate anyway even if they did.
So plenty of pressure, I then tested electrically. Looking at this diagram
http://showerdoc.co.uk/shower-spares/triton/topaz-t100i-electric.html
I metered across thermal cut-out on top of the heater can assembly and found 240v both sides i.e. looks like switch is normally made during operation. I then metered across the switch on the outlet pipe assembly which says it is also a TCO in the shower manual and this gave 24v whilst in use on both sides so looks normally made during operation also. What I am really curious about is how this unit can bring up a low pressure warning light when the only sensors I can find are the 2 TCO (thermal cut-outs), it makes me doubt the bottom one is a thermal cut-out and is maybe is in fact a pressure sensor. But it refers to this as a TCO several times in the manual so how is it detecting pressure, where is this mystery sensor?
I have played with the stabiliser valve with the cover off, i.e. I have found it goes much further than the dial on the front cover will allow before hitting its true stops. By doing this I managed to get a really powerful shower going, only trouble is the heaters could not cope and cold water came out even though the both heater relays were energised thus energising the elements, and therefore trying to heat the water. You may ask why I messed about with this, well the reason I altered it was because I found that the low pressure light extinguished doing this as if the pressure coming out of the outlet was too low in pressure and that was causing the problem. Next to try and get optimum performance from the shower I started turning it so it gave maximum pressure but cold water and then slowly turned it down to decrease the water pressure coming out of the hose until it was producing hot water, thus giving me hot water at the best pressure this shower can manage. By then turning the dial on the cover to maximum and fitting the cover back, it was set to give that pressure at that temperature at maximum.
By doing this I thought I had cracked the problem as it seemed to be working the best it could with no faults, but I then turned it down with the cover on as per normal use to 9, the setting my father uses and in seconds the low pressure light lit and the water went cold and would not stabilise. I had to turn it off and on again to get it working. But now as before i touched it, it brings up low pressure whenever it is turned to 9 or below, so I have actually achieved nothing.
My guess is that the outlet assembly contains a pressure switch and not a TCO otherwise how does it detect pressure is low? If I am right this needs replacing as the shower water comes out with reasonable pressure although nowhere near 5 bar I reckon, which is a great pity as I have proved you can get a load of pressure out but only if you like it cold.
Anyway I would appreciate any help as I am stuck now.
