Hammer with Gorton #4 but not with Hoffman 1A

malex

I have a small sunrad in the bathroom on the second floor (3rd to last on the long main). A few months into the heating season I switched all vents to gortons and put a 4 on this one. I never heard any noise from this rad prior to the switch but started to hear faint water hammer (if that is what it in fact is). It is not very loud but very faint thumps and they started slow with several seconds in between in the beginning of the cycle until it ended in a drum roll. But it will keep you up at night (mostly because I am going over all the potential causes in my head). It also sounds like it coming from the run-out from the riser (about 5') or he riser it self as it runs from the wall under a closet into the bathroom.



I put on a Hoffman 1A a few days ago and have not heard a noise since. But it also doesn't heat unless it's cold out and cycles are long. I am assuming this has to do with Hoffmans bing slower, even at 6? Is it that there is too much steam too quick with the gorton? Any other ideas as to what is causing the noise? Pressure is low and rarely above 1psi (at the end of a long cycle).



I was wondering if pitch could be the cause, either in the run-out or the rad itself. But how do you pitch a small sunrad as the supply doubles back so if you pitch toward the supply you actually restrict drainage?

nicholas bonham-carter

Hoffman the winner

Have you checked your thermostat for settings/anticipation, just make sure the burn cycles are long?

How is your main venting? If it is not generous, the radiator vents will be trying to do a job for which they are Ill equipped , namely venting more than the riser, and the radiator.

As always keep your pressure low, verified by a good low-pressure gauge (don't rely on the pressuretrol settings).--NBC

malex

Pressure is low

Have 2 gorton 2s on the long main and pressure is low, just above 0 until saturation.



Could it be that with the low pressure the steam is travelling to fast up the riser with a gorton 4? This rad is just after a 90 bend on the main and the steam has been picking up some speed by then?

Patrick_North

Gorton #4 is slower

Setting a Hoffman 1A isn't an exact science, but wide open it should have substantially more venting capacity than the Gorton #4. Maybe you have a bum Hoffman vent? The Gorton #4 is on the slow side- I'd investigate for problems outside of the vent.

What was a radiator vented with before? Did it heat well?

A sagging runout could be holding on to extra condensate- you could check all connected pipe and the radiator itself for proper pitch.

Good luck,

Patrick

malex

Good point

I will try another 1A and see if this one has just gone bad.

Before I put the gorton on there was a unknown vent on there (no stamping on it). It looked kind of like a vari valve but instead of the slider there was a ring around it with holes of increasing size that you could slide over the orifice to adjust the venting rate. i will see if  I can upload a pic.

It was working fine and was set to a huge vent hole but it gave of a fog horn type sound under just a little bit of pressure.

ChrisJ

Hoffman 1A

The Hoffman 1A can be set anywhere from wide open to completely shut.



In fact I have 2 vents which are marked slightly off.  If I set them to #6 the hole is almost completely covered while set to #5 its wide open.  Side to side slop in the caps also allow a wide variety of adjustment while still set to the same number.



Remove the nut on top and look at how the cap lines up with the hole.  You may find your Hoffman 1A is venting slower than a Gorton 4.  Another easy test is to simply blow through it with your mouth but this requires removing it.

Don't get me wrong, the 1A is still a good vent, they just take a bit to get adjusted.  Also be careful tightening them, I believe you are suppose to do it by hand but I use a nut driver just so its easier for me to hold the cap where I want it.  I crushed the tabs on one of the nuts and had to steal one from a spare vent I have,

Hap_Hazzard

I had a similar experience

I replaced a couple of air vents on two radiators that weren't heating well with a Gorton 5 and a Gorton 6, even though the vents I was replacing had vent ports slightly bigger than the #6, and both radiators started blasting every cycle. My surmise is that the old vents had an accumulation of scale and weren't venting at their full capacity. I have one of them soaking in vinegar now just to see if it changes anything.