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How do I increase the water temperature on my Artos F904A-VO valve?


If there is warm or hot water coming from faucets near the shower system, (or cannot get hot water from hot side of faucet) please check valve as follows:
1. Turn off the service stops and see if this rectifies the problem. If yes, this verifies that it is the shower valve causing the crossover issue
2. Are non-return check valves moving freely? If not, clean or replace
3. Is there debris or mineral build up on the check valve seating? If so, clean carefully to ensure a good seating.
4. If the check valves and seating are ok and there is still cross over occurring, please check the hot and cold pressure. There should be a difference of no more than 20%.


Insufficient hot water

If there is cold water crossing over into hot, please first fix this issue as above.

1. Loosen the set screw on the handle and remove along with the backplate. 
2. Then, with the temperature limiting ring removed, rotate spindle on the cartridge  counterclockwise as far as possible. The temperature should be max. 120 degrees F. If it is significantly lower, use a 2mm Allen wrench through the end of the cartridge spindle (see attached diagram) and turn counterclockwise to achieve the desired temperature.

Please note, instantaneous water heaters are not recommended for high flow thermostats such as the F904A-VO.


Download Cartridge Diagram



Updated on 20 Oct 2023