I have a Heatguard TMV2 thermostatic mixing valve fitted and when the cold water supply fails the valve continues to allow water through. Is the valve defective?
A – Unlikely. The most common cause for this complaint is a too low differential temperature. There must be a minimum of 15 deg C ( 9 deg C for ProMix 22-2 and Heatguard TMV3-8) between the hot inlet temperature and the mixed water outlet temperature for the fail-safe feature to function. If system conditions are correct and the fail-safe does not work then the valve should be dismantled and the internal shut-off seat cleaned and the piston re-greased.
Related Questions
- I have a Heatguard TMV2 thermostatic mixing valve fitted and when the cold water supply fails the valve continues to allow water through. Is the valve defective?
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