# Sealing Heatilator vents with a gas insert



## CurlySweep (May 26, 2017)

Greetings all,

It has always been my understanding and policy that the upper and lover vents on an old style heatilator must not be sealed over.  I have a customer that is quite insistent on it, since they are installing a gas insert in the fireplace, so I thought i would ask.   I know that it would not be suitable for wood burning with the vents sealed but I can't seem to find the definite answer about the gas insert configuration.  Thank you.

Matt


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## Tech Guru (Jun 12, 2017)

well, the simplest way to put it is like this:  The gas insert must be installed in a_ code compliant _wood fireplace, be that a complete masonry site built unit, a heat form (i.e. a steel constructed firebox, with inlet and outlet circulatory system, intended for use with masonry site built fireplaces) - which is what I suspect you have -  or a wood zero clearance (aka prefab) fireplace.  The gist is, if the grills are required to be there if it were in use as a wood burning fireplace, they should be left unobstructed with the installation of a gas insert.


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## bholler (Jun 13, 2017)

If it is a heat form or metal box in masonry you can seal off those vents as long as you use noncombustibles.  If it is a zeroclearance unit you cannot and you should really check to make sure the zc unit allows for an insert of any kind to be installed in it.


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