Pressure Drop During Call for Pumps

Dave 1234 · Post by **Dave 1234** » Tue. Apr. 08, 2014 7:50 am

Good morning,
I need some education about change of pressure during a call for heat. My buddys new system changes pressure every time the pumps start up. He checked his X-tank, its ok. and his system has two X-tanks.

Whats the deal ?

Dissclamer, Heating systems are only a novelty hobby for us. We are not pros. Nope !

Thanks !!!

Dave

Carbon12 · Post by **Carbon12** » Tue. Apr. 08, 2014 8:58 am

Air in the systems???

Post by **Rob R.** » Tue. Apr. 08, 2014 9:58 am

Where are the circulators, expansion tanks, and pressure gauges located in relation to each other?

Dave 1234 · Post by **Dave 1234** » Tue. Apr. 08, 2014 11:15 am

Rob, Carbon 12.
The boiler is in an out building , a x-tank , circulator , air bleeder and pressure gague is at the boiler .Also all of the above in house at the oil burner too.

Dave

Sting · Post by **Sting** » Tue. Apr. 08, 2014 12:30 pm

long read - but this question will need it...

http://www.heatinghelp.com/article/343/Circulator ... ure-Change

carlherrnstein · Post by **carlherrnstein** » Tue. Apr. 08, 2014 5:32 pm

I would imagine that its normal for the pressure to drop when the circulator pumps come on because liquid water expands when heated and contracts when cooled. The water in the boiler is hot and expanded(higher pressure) then the pumps come on and the boiler water starts to cool off and contract(lower pressure)

However I'm not a hydronic guy an this is only a hypothesis.

Sting · Post by **Sting** » Tue. Apr. 08, 2014 6:05 pm

carlherrnstein wrote:I would imagine that its normal for the pressure to drop when the circulator pumps come on because liquid water expands when heated and contracts when cooled. The water in the boiler is hot and expanded(higher pressure) then the pumps come on and the boiler water starts to cool off and contract(lower pressure)

However I'm not a hydronic guy an this is only a hypothesis.

Please read the link I provided - it directly address's this

carlherrnstein · Post by **carlherrnstein** » Tue. Apr. 08, 2014 6:25 pm

Very interesting.

Dave 1234 · Post by **Dave 1234** » Tue. Apr. 08, 2014 6:47 pm

Sting,
You find a way to simplify heating that I can grasp. I read it and do see why you pointed to this article.
Makes sense !
Thank-you ........Again

Dave

Sting wrote:long read - but this question will need it...

http://www.heatinghelp.com/article/343/Circulator ... ure-Change

Sting · Post by **Sting** » Tue. Apr. 08, 2014 7:41 pm

good deal