I have just got home from a frustrating investigation.
The original problem was a lack of temperature water in the basin tap. This was because there was debris in the check valves of the thermostatic shower valve and there was a back pressure onto the combi boiler. Also, the valve was connected the wrong way round (hot / cold) Now these two items are rectified,I find that the shower valve will turn off the hot flow in the 'cold' temperature setting, but mixes in too much cold with the hot at the hotter end of the scale, and so produces only a lukewarm shower. Ironically, when the valve was connected the wrong way round, it would at least provide hot and warm water, even if not thermostatically regulated, because it was shutting off the cold (instead of the hot) when in the cold water setting!
If I isolate the cold supply, only then do I get a hot shower (too hot, of course). Bathstore are sending a replacement cartridge, but were adamant that I would need to fit a Pressure Reducing Valve because the combi heated water pressure into the valve would be a little lower than the mains cold into the valve. I am sceptical of this, and Dan Robinson seems to think it is a flow restrictor, rather than a pressure reducer that I might need. I am confused. Any input out there?
It's a 'Metro Vertical Thermostatic Bath Shower Valve fed from a Potterton Performa HE 24.
The original problem was a lack of temperature water in the basin tap. This was because there was debris in the check valves of the thermostatic shower valve and there was a back pressure onto the combi boiler. Also, the valve was connected the wrong way round (hot / cold) Now these two items are rectified,I find that the shower valve will turn off the hot flow in the 'cold' temperature setting, but mixes in too much cold with the hot at the hotter end of the scale, and so produces only a lukewarm shower. Ironically, when the valve was connected the wrong way round, it would at least provide hot and warm water, even if not thermostatically regulated, because it was shutting off the cold (instead of the hot) when in the cold water setting!
If I isolate the cold supply, only then do I get a hot shower (too hot, of course). Bathstore are sending a replacement cartridge, but were adamant that I would need to fit a Pressure Reducing Valve because the combi heated water pressure into the valve would be a little lower than the mains cold into the valve. I am sceptical of this, and Dan Robinson seems to think it is a flow restrictor, rather than a pressure reducer that I might need. I am confused. Any input out there?
It's a 'Metro Vertical Thermostatic Bath Shower Valve fed from a Potterton Performa HE 24.