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Hi!
Can I use a tempering valve connected to low pressure hot water and high pressure cold water?
The piping diagrams I see on the suppliers' websites show both pressures the same (both low or both high) or mention a ratio of no more than 5:1 (not for all valves).
On the other hand, people appear to have had tempering valves connected low hot / high cold and they work just fine.
Second question: the Code I believe is asking for Tenpering valve on all "personal hygiene fixtures". I have a bath tub, a shower and a hand basin in the same bathroom
- do I need a valve for each "fixture" (3 valves for that bathroom???)
- can I use Tempering valve on the shower only but not the bath tub and the hand basin? Is this against the Code?
Many thanks.
Chris
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Chris,
It is OK to use a tempering valve on a low pressure hot water system where the cold water is on mains pressure. The tempering valve or most shall I say, are fitted with a non-return valve to stop the cold water pushing through to the hot side.
As for your bathroom, you only need one tempering valve fitted to your system that supplies all your fixtures. This is generally fitted near to the hot water cylinder on the outlet side. You must ensure that tempered water is supplied to all your sanitary fixtures, not just your shower. Remember, the valve is factory set to 55 deg so the water is still hot enough for a bath or basin. Anything over 60 deg has the potential to scold.
Obviously, installing a tempering valve will temper all your fixtures throughout the house so in rare curcumstances, owners have a hot water feed prior to the tempering valve available to deliver to the kitchen or laundry tub, but not necessary.
Hope this helps
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I thought tempering valves required equal pressure coming from both sides so that the water mixes properly. Ive never installed one on low pressure hot with mains pressure cold and cant see how that would work.
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There are two types of tempering valves, one kind is only for mains pressure but you can also purchase a tempering valve for low pressure systems (larger mixing body and non-return). These tempering valves are very common with retrofit solar systems on low pressure systems. Look at the APEX manufacturer specification.
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balanced pressure is recommended but you can have 1 5:1 ratio of cold to hot. You learn something new every day! I think I will keep installing them balanced though