Zone valve for water heater.

[fuddster]

My daughter lives in a condo with about 60 - 70 units in the building. She lives about 400 miles from my location and I visit from time to time with her
mother. We usually stay for several days and so, of course, showers are needed. Her hot water is supplied from a central source in the building and not in her unit. The water temperature varies wildly from a comfortable adjustment to suddenly going cold and then very hot. This happens all the time and sefveral other units have complained. She has replaced all the faucet cartridges at the managements suggestion. They claimed this could be the cause. The maintenance man that changed the cartridges said it could be a zone valve problem. When my daughter asked about this she was told by management that the zone valve is each unit's responsibility and not the building's (read management's) responsibility.

Could a zone valve cause this water temperature fluctuation and where would this part be installed?

Any help with info would be greatly appreciated.

 

[hj]

hot water

I have NO idea what a "zone valve" would be, or how it could cause the problem. But if the tub/shower valves are either Mixet or Moen, they can cause that problem, especially if several are defective. BUT, the problem valves are usually in other units, not the one having the difficulty.

 

[Sponsor]

 

[Jadnashua]

Pressure variations can play hell with trying to maintain a consistent temperature in a shower. A properly working pressure balance valve should minimize that effect. There are a few brands of valves that, when closed, allow the hot and cold to cross-over. This, as HJ indicated, can create the inability to get really hot water in other parts of the system, since instead of being all hot, it is already mixed with some cold. If that's the case, everyone would need to replace their valves with a brand/style that doesn't have that problem (it's a failure mode, but is fairly common on some).

Another possibiity that might work, is a thermostatically controlled valve. It might work a little better, but there's no guarantee. I used one in a hotel in London once where the pressure varied quite a bit, but the shower never varied much (the volume did, though). It was a Grohe valve. I'm sure others may work, too.

In my view, this is a safety issue that the association should address. I'd go before the board, and if possible bring it up at the next annual meeting. It might give you a feel for who actually has the same problem, and might indicate a source of the problem and suggest a fix. Keep in mind that in a condo, YOU are one of the owners, and all of you share a role in providing a decent place to live.

 

[flamefix]

Could it be related to the response time of the mixer valve in the shower combined with demand for hot water from units closer to the source of the hot water.

I'm imagining there is a secondary return (hot water loop) in the block but if not or even so could there be an issue with the supply side of the plumbing causing this.

Feed back from others living there would help to establish who does and doesn't suffer and if there is any correlation.

Jadnashau are you referring to the balanced cold take off point on the Pressure regulating valve which would equalise the hot and cold pressures giving problems? Because it occurs to me that it could also be that if the hot supply is after the pressure regulator and the cold feed is direct to the cold main (ie before the regulator) then that could be equally affecting hot and cold to the shower mixer as the pressures would not be at times equal. Again this is an installation issue which should fall to the management not the owner.

 

[Jadnashua]

I was referring to a failure mode of some shower valves (well, I guess it could happen on other types of valves) - when off, they allow cross-over between the hot and cold side.

Re the zone valve...you could really have one attached to your condo, but typically, it would be in the space heating circuit, connected to your thermostat and not have anything to do with your water heating. Unless, you generate your own hot water, it could control an indirect WH (but I think you said your hot water is common).