Jim,What fan did they use?There was no picture of the fan.If you look at the gauge you will see the needle is at 2-3/4” vacuum.I wonder if the fan is properly sized or if it is outside the manufacturers recommended operating range.A Magnehelic is a great upgrade to a U-Tube. Not that one but there is a good substitute.Most home owners can’t read the U-Tube & it really is a piece of junk not a quality measuring device.I am sure it has never been evaluated by UL or any other testing agency for accuracy.We use the Mini-Mag from Dwyer upon occasion. Mostly when we have to place the vacuum measuring device outside.Series 2-5000Minihelic® II Differential Pressure Gage This unit cost around $30 & it comes in different pressures. We buy 0” to .5”, 1” to 5”, & 10” to 50”.Dwyer also makes a digital micro manometer that reads to .000” for under $300.These units can be bought calibrated is desired.http://medallionofmissouri.com/services.phpI assume this work is done in Missouri.If you look at the “Radon System” label you will see the absence of an RCPP#.I assume that state is an unregulated state.Is that correct?It is nice to see that the contractor actually determined the light fixture & receptacle the fan is plugged into is on a switch.This is a mistake I expect every mitigator has made.The remedy of putting electrical tape over the switch as a solution is funny.Of course they used “electrical tape” so I guess that conforms to code.Ha! Ha! Thank You, David Grammer27 Ironia Road, Unit 2Flanders, NJ 07836973-927-7303 phone973-927-8221 fax www.radata.com From: International Web Resource for Radon Professionals [mailto:RADONPROFESSIONALS@LIST.UIOWA.EDU] On Behalf Of Dave HillSent: Friday, May 13, 2011 7:51 AMTo: RADONPROFESSIONALS@LIST.UIOWA.EDUSubject: Re: [RNPROF] FW: Dwyer Magnehelic gauge I have used magnahelics in the past, but it was always for a commercial project. Mags are specified in most soil vapor extraction jobs.What alarms (pun intended) me more is the potential fire hazard that kind of wiring job creates.Does the tape constitute a switch lock out? From: International Web Resource for Radon Professionals To: RADONPROFESSIONALS@LIST.UIOWA.EDU Sent: Thu May 12 23:55:26 2011Subject: [RNPROF] FW: Dwyer Magnehelic gauge From: Jim Medley [mailto:info@radonsystems4u.com] Sent: Thursday, May 12, 2011 11:52 PMTo: 'RADONPROFESSIONALS@LIST.UIOWA.EDU'Subject: Dwyer Magnehelic gauge To all: Ran across a system install the other day where a contractor had installed a Magnehelic gauge on a radon system ( see photos ) besides being a expensive item for no reason I had never seen one on a radon system install. Has anyone every installed one of these? ….and of course for what purpose ? other than to burn money…. I do not know why. You might also note the wonderful install on this systems wiring. They drilled a hole and took the electrical service wire through the system piping as it went through the house and then brought it back out once they were at a power source…..Please also note the other wonderful electrical issue etc on this system install. Jim Medley Radon Systems 4U LLC ********** RN PROF (Subscription changes - archives) - http://list.uiowa.edu/scripts/wa.exe?SUBED1=RADONPROFESSIONALS&A=1 *********** ********** RN PROF (Subscription changes - archives) - http://list.uiowa.edu/scripts/wa.exe?SUBED1=RADONPROFESSIONALS&A=1 ********************* RN PROF (Subscription changes - archives) - http://list.uiowa.edu/scripts/wa.exe?SUBED1=RADONPROFESSIONALS&A=1 ***********