Mystery valve

[RobC]

"I don't understand about the working erratically part and defeating the purpose of supplying instant hot water.

When the temp in the supply line drops,......."

Precisely, we don't want the water to drop in temperature at any time during our peak demand period. If I understand you correctly you suggest placing a temp control at the demand point and activate the circulator when the water falls under a pre set temperature.

What would happen if you turned on the faucet at the time the control called for 'pump on'. That condition would not satisfy your original design criteria that of always having available hot water on demand.

How Long?

That would depend on the occupant(s) and their lifestyle. It could be a half hour or two hours in the morning and the same in the evening. Or multiple occasions, for instance the husband leaves early morning, children a bit later and perhaps the wife starts work at 10:30 am etc. It could also run continuously on certain days.

What about Erosion?

I don't see this problem here and we have millions of miles kilometers of radiant heating without any reported failure due to erosion. It may have something to do with water quality and chemical composition, I don' know. I understand the chlorine content is higher in the States. Perhaps Jim could elaborate on his observations about this.

Circulator design can vary greatly depending on the application, if we're discussing commercial, then that would be a horse of different color(s). The demand criterion's are more complex in design than residential.

"I can pick up on many different styles and systems and create my own "what works for me".

AND isn't what's it all about ...........sorting through all the information and making an informed decision.

Kind of tough when you don't have any information to sort[:-graduat

[StevenT]

I REALLY DON'T THINK YOU UNDERSTAND ME CORRECTLY, so I'll try to explain myself a little better, perhaps I was not as clear as I should have been. My error.

The temp sensor is NOT at the delivery point, it is on the loop.

"HOW LONG" ... 1/2 hour, two hours, multiple occaisions, somtimes continous (as in all day?)... Hmmm

The purpose of the sensor is to monitor the temp in the loop. Always keeping the water in the loop hot, so WHENEVER you open a valve at the delivery point, it will receive HOT water. Set it and forget it!

Once the water in the loop is hot, I don't see the advantage of running the pump.

With a sensor, ALL THE TIME there would be instant hot water.

With a timer, AT TIMES there would be instant hot water.

If controlled by a sensor, do you think it would operate for more than 30 seconds (depending on the volume in the loop), every half hour or so? That's a total of about 1/2 hour for a 24 hour period.

Furthermore, during peak time, isn't the water in the line already getting hot, simply from using it?

Now as far as commercial applications, it came to mind that at the laundromat, I utilized both a circulator and a timer. The boiler (entire system)was on a timer. I would turn on the boiler when opening, the timer would shut off the boiler shortly before closing. When the system was on, the circulator would operate when needed, and only when needed. I also hooked up motorized louvre vents,(1 high, 1 low)for fresh air, that would open when the boiler fired.

Anyway, Did you hear the one about the guy who walked into a diner with an ostrich?

Peace []

[Jim Katen]

Originally posted by RobC

. . . What about Erosion?

I don't see this problem here and we have millions of miles kilometers of radiant heating without any reported failure due to erosion. It may have something to do with water quality and chemical composition, I don' know. I understand the chlorine content is higher in the States. Perhaps Jim could elaborate on his observations about this. . .

Are your millions of kilometers copper or plastic?

Around here, when a circulator's been running 24/7 for 20 years or so, we see holes develop in the copper, often around the 90-degree elbows. A plumber friend tells me that the failure at the ells happens when the installer fails to ream out the copper tube after he cuts it with a rotary cutter. He says that the burr causes eddies in the water that, in an ell fiting, cause water to wear right through the copper. I don't know if his theory is correct, but I have seen failures near ells.

I suspect that mineral content and water chemistry have a lot to do with it.

- Jim Katen, Oregon

[RobC]

The in slab radiant piping is mostly PEX although I've see a few Poly B systems and I recommend to monitor closely.

Copper and brass controls are seen from the manifold to the boiler.

I have to admit that radiant is relatively new for us and reserved for higher end homes. For the most part, systems are less than 20 years old and perhaps the reason we don't see failures yet.

I agree wholeheartedly about the importance of reaming the copper system. Turbulence and as you say eddies can wreak havoc not to mention reduce efficiency and volume.

Here is a typical installation

Download Attachment: HeatingBoiler_M.jpg

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FYI- PEX come in different colors- for identification purposes only

Red - for hot

Blue - for cold

White - for both

[BADAIR]

Attic plumbing insulation absence was in the report.

Buyers walked today because the builder said "your inspector has picked this to pieces"

I guess for a brand new condo stucco below pavement-soil, 34" wide stairways, current plumbing leaks at service stop valves, accessible parking, inactive under ground garage sump, absent AFCI's at 2 of 3 bedrooms, neutrals mutli tapped...

I am too nit-picking.