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DS1820 on Boiler

Posted: Tue Dec 29, 2009 8:28 pm
by Merdeka
Hi all,

I've just installed 3 DS1820's on my boiler pipes. They monitor the temp for domestic water, central heating and central heating return.
What I did was, Solder a piece of flatcable to them. Heatshrink the open metal and tie-rap them to the pipes. Then a piece of electrical tape around them until I get my hands on a piece of heat insulation foam to put around the pipes.

That I am interested in is this:
Do U think the temperatures I read now are correct? Because the DS1820's are on the outside against the pipe. Or do I need to put some kind of calibration?

The domestic water-pipe is copper. The central heating is iron/zinc I guess.

Re: DS1820 on Boiler

Posted: Tue Dec 29, 2009 9:28 pm
by Digit
Maybe your boiler has a status panel? Maybe there's a way to display values of the internal sensors.
Then compare them with your own readings from the DS1820s.

Re: DS1820 on Boiler

Posted: Wed Dec 30, 2009 1:42 pm
by phoenixb
In theory you are right, you can considering the various heat losses you have like as thermal conductivity (Lamdba λ).
But in practice that temperature measurements loss are minimal.

The method I use myself in the refigiration has some contact pasta (i don't know is this is the correct english translation) with the sensor mounted on the pipe and then what Armaflex insulation or other insulating material on it that gives the best results.

If you have some time :wink: you can also mount an immersion tube into the pipe that you can use for it.

Re: DS1820 on Boiler

Posted: Wed Dec 30, 2009 2:09 pm
by Merdeka
I have thought about using the boilers own sensors. It uses NTC's. However I didn't really want to tap into the system. The house is a rental that's why.
Tonight I'll go get some insulation and try this setup for a couple of weeks.

So my theory is this:
The pipes will be about the same temp as the water inside them. And the temperatures I read are the water temperatures delayed the heating of the pipes.

Correct?

Re: DS1820 on Boiler

Posted: Wed Dec 30, 2009 2:28 pm
by phoenixb
Yes that is correct.

Question what for boiler have you?

Re: DS1820 on Boiler

Posted: Wed Dec 30, 2009 3:06 pm
by Merdeka
It's an old Vaillant Hr Solide 18-22C. Old type without opentherm.

Re: DS1820 on Boiler

Posted: Mon Mar 01, 2010 8:04 am
by 747driver
I'm sure your method will be quite accurate.
Wouldn't use the boilers own sensors.
The DS1820 are easier to interface.
Guess it will be more interesting to see the in/out temperature difference than having a 0,1 degree accuracy.