Thermostatic Bath and Shower mixer

neilmcl

Is there such a thing as a deck mounted thermostatic bath/shower mixer where you can override the thermostatic safety when running the bath. As we know thermostatic mixers don't normally allow the hot water to reach over around 45C which isn't great when running a hot bath, by the time the bath is filled it's usually tepid at best. Are there any  mixers that disable the thermostatic feature and allow hot and cold water to run straight from the pipe.

knightstyle

Ours has a button on it you can press to go hotter than the anti scald setting.  Also you can alter the max temp with an allen key under the end cap.

neilmcl

knightstyle said:

Ours has a button on it you can press to go hotter than the anti scald setting.  Also you can alter the max temp with an allen key under the end cap.

The safety button is usually around 38C but on max temp I thought you could only get around 43-45C. What make is yours?

knightstyle

Don't know it was there when we moved in.  Just a cheap bar type.

neilmcl

knightstyle said:

Don't know it was there when we moved in.  Just a cheap bar type.

I've a had a look round and even if it has an adjustment for the max temp you still can't get these to get above 46C by design.

Another_Level

There was a market for these items, have fitted many 'mira extra' deck mounted shower thermostatic mixers in premier lodge- travel inn hotels and bg work.

they have been sold under other names like 'bristian java' and a few more. maybe some information on showerdoc.com. youl need to search.
These and other similar historic deck mixers work very well, there expensive but when it comes to anti scald showering with un thermostatic full flow bath tub filling they were the only units around. 

Now days i would look at doing some more work and install a separate thermostatic (sequential type ) thermo shower mixer valve. Fed from the balanced pressure/flow pipes which supply standard pressure bath taps.

Think the mira extra items were not a popular item ££ and those already fitted are well serviced 

akira181

I would question whether or not your water heater is working correctly and not the thermostatic mixer for two reasons (speaking as a water safety assessor where taking temperatures and setting TMVs are part of my job).

1st is that 45C is too hot for a bath.  5 minute exposure to 48C water can result in 3rd degree burns.  The max recommend temp of a hot tub is 40C and even that's on the too hot side for a lot of people.  38C is the recommended for showers, a degree or two higher for baths to account for cooling and acclimatisation, no more than 43C for healthy adults (lower for the vulnerable i.e. elderly, babies, etc).  This is based on experience and guidance from the Chartered Institute of Plumbing and Heating Engineering.

2nd is that even the cheapest of fibreglass baths with no insulation will retain temperature long enough for it to fill at the very least without cooling noticeably unless your hot water flow rate is extremely low (suggesting an issue with the water heater).  If you are filling with 45C water, it shouldn't have lost more than 2C if that.

Are you sure the hot water is not running cold at some point during the filling process?  If your hot water is tanked, do you have enough capacity/storage temperature to fill a bath?  Do you know what temperature the water is coming out the mixer at?  More often than not, the valve has not been set properly or the water heater properties have changed with age and the temperature written on the dial is not representative of what's coming out the outlet.