Lochinvar WHN keeps tripping Relief

Colin47

Hi everyone, this is my first post to this website, been reading it for a while.



My company installed a Lochinvar WHN 155 about a month ago and it seems like air is getting trapped in the system. I have gotten 2 call backs because the boiler made "a grumbling noise" and the pressure relief tripped and dumped water on the floor. I am assuming that the main boiler loop (primary loop) is getting air bound causing it to flash steam inside the boiler tripping the relief, but Im not sure because I am never there when it happens.



System info:

WHN155

primary/secondary

2 zones on secondary

1 zone is a converted gravity system

second zone is a regular copper fin baseboard loop

superstor is run off of the primary loop

extrol 60 exp tank

15PSI in gauge



There is a 1-1/4" spirovent on the supply side before the circulators, it is about 3 inches from an elbow. We have bled the system out for days and bled the radiators out, but can still hear air moving through the system. Any ideas? is the spirovent to close to an elbow?

Would extra air elimination devices help? Any input would be greatly appreciated.

Timco

Piping

Any piping that would trap air?



Does your Spiro have some flux keeping it closed?



Did you purge? I always purge each loop / zone.



Air trapped in boiler? After fill, try letting air out through relief or gauge?



You must purge.

kcopp

I would pull.....

the spirovent apart. Do you have some pix? What size are the circs? and what size in the boiler? Purging out the old gravity part will be a bit of a challenge as you cant "purge" out each rad. Gotta rely on the bleeder vents... How well did you clean the old gravity piping? There is a lot of old ferrous stuff that can gum up a system especially if a gianonni HX is involved.

Zman

Piping

A picture of the boiler piping would help.Where is the exp tank?

Carl

hot_rod

vent on the HX

does it have a manual, or float air vent on the header inside the boiler? Often that needs to be checked.