maybe i boo booed

theprentice

i piped a 50 gallon gas fired water heater today supplying both domestic water and heat to a small 300 foot loop of in floor heat for a garage. tempering valve for the domestic and used a heat exchanger for the heat. while driving home after finishing i realized i completely forgot to pipe in a relief valve on the heat side. i immediately began cursing myself for my idiocy. i've got the purge and the expansion tank and the bleeder and the gauge but in my rush to finish within a reasonable amount of time i forgot the relief valve. when i returned to the shop i informed my employer of this and he nonchalantly said, no big deal, it's a small heat exchanger not really any need for it. now i've only been ini this field for a year and a half but i've been doing my own homework. i know i read in modern hydronic heating that any heat source even when connected to a separate heat exchanger requires an expansion tank and a relief valve. i haven't double checked but i swear i remember reading that. anyone have any thoughts on this before i double check.

thanks

Unknown

yes...

Yes, you should have a relief valve on the heating side,esp with the prv connected to it.... We all make mistakes , its the wiser person that catch it him/herself and corrected it... Now, have a good weekend..

Mike.C

yup

I agree. You have thermal expansion in the system. I have seen in a system I did that without the expansion tank it kept running out of water. I finally watched the boiler and saw that if I filled the system to 20# that as the water heated it would increase and increase and finally blow the 30# relief.
Side note. I did know to put in the exp. tank but it was on backorder from our supplier so I installed a ballvalve in it's place to make later installation easier.

Mike.C

Unknown

Good Call For Yourself,

and I agree with everyone above,,get back and put one-on ASAP.

Dave

hot_rod

Does B&G still offer that combo

fill valve/ relief valve? That would be a simple way to add the relief without a lot of piping.

hot rod

Unknown

good point, Hot Rod...but

Good point, Hot Rod, but what's the rating of that relief valve? I had to remove them because there's no tag on them. I asked everyone from B&G reps to company and no one can answer this one. They all say they will get back to me.. Never did... I gave up and don't install them, since no tag and the unit is not fast fill ethier...

kal_2

i'd be more worried about the floor..

chilling the tank below 120f - and then showering and breathing that water vapor - leigonella bacillus anyone???

Mitch_5

I believe they make

water heaters certified for heating that have seperate tapping's and a built in heat exchanger. Was this heater listed for both applications.

I cannot see it being difficult adding a pressure relief valve but you must make sure there are no ball valves between the heat exchanger and the relief.

Always think in terms of building a little boiler. We do similar systems off FHW systems if we want to add anti freeze to only one loop. Still have to have all the bells and whistles.

We all do things that after we left the job and say to our self what was I thinking of!!!

Side note: You stated you have been in the trade only a year, I would have to say to your boss why were you on your own?

Mitch S.

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theprentice

thank you all for you response. i felt the same way about the situation. in regards to the last post, yes, i've only been in this trade a year and a half. 22years old. i feel that i've learned an incredible amount in that time but i'm still not comfortable having to make some of the decisions i have to on a regular basis. small shop, i'm one of two employees the other being a service guy. i understand enough of the heating to get the job done. I guess? most importantly i can pipe and make things look good. so i guess that gets me by. i don't agree with the situation either and this upcoming week will be my last with this employer. i signed my union papers on thursday and feel that the opportunity for a continuing education is simply something i can't pass up. plus i'm tired of being shop b*&$h, office manager, landscaper, drywaller, electrician, and field foreman. I want to learn this trade but i don't want to have to do it by myself.

thanks again guys.