This radiator has given me trouble

tsayles50

Hey all so I’ve posted about this issue before but not in a cohesive story. 

When we bought our house last year and I had some radiators that weren’t heating up or, this one, when it would heat up the air vent would spit steam. I replaced air vents on the cold radiators, including this one. I bought the varivalve ones because that’s what my father in law recommended. 

After replacing the air vents the other radiators all warmed up, including this one. But this will still occasionally spit steam. I tried manipulating the slide thing on the varivalve vent to limit the output and that hasn’t solved the problem. If it’s relevant this radiator is generally the slowest one to heat up. 

I believe the pitch is correct, I took a level and it indicates it is pitched downward rowed the valve at the floor. I don’t know the angle of tbt pitch. 

There is a strong correlation between this radiator spitting steam and our boilers water level dropping.

I had a lot of work done to the piping near our boiler and I know the main are vents are correct.

-Tim

neilc

well , , , ,
show us your boiler,
what pressure is it running?

back at that rad,
can the whole rad be lifted up? Carefully?
possibly the pipe to it needs better pitch?
can it lift and sit on 3/4, or 2x4 blocks?
can you see its supply from below? picture?

neilc

one more thing,
is that rad valve fully open, it should be,
maybe the disc inside has fallen loose,
any gurgleing when the vent is spitting?

tsayles50

neilc said:

well , , , , show us your boiler, what pressure is it running? back at that rad, can the whole rad be lifted up? Carefully? possibly the pipe to it needs better pitch? can it lift and sit on 3/4, or 2x4 blocks? can you see its supply from below? picture?

Pressurtrol, at correct pressure.

I haven’t been able to move the valve at the base since we moved in, I’ve been assuming it’s open. Not sure how to loosen it. 

I have tried lifting it to put a quarter or two under it but it’s heavy. That’s when I grabbed my level instead. It’s also got the sink next to it so it’s awkward. Is there a recommended strategy for lifting radiators?

No gurgling at all when it spits that I’ve heard. but I will be sure to assess for that specifically next time. 

This morning when it was warm there was no spitting. I may be going crazy over something that inconsistently going wrong. 

I think the pattern is: if the temperature at the thermostat needs to go up 2 degrees or more then it spits. For example: the other day I had the heat off during the day, it was an oddly warm day with a sharp drop in temperature before bed. The temp in the house was 68 before going to bed. I put the heat to 70, we have a 2 year old and a 5 month old so we want it warm. The radiator spit. Last night the temp in the house was 69, when I put the thermostat up to 70 no spitting.

-tim

dabrakeman

Do you know what the actual pressure is when your boiler cuts out on the long cycles, i.e. when you are doing the 2 degree recovery? Your setting on the pressuretrol seems right (assuming the dial inside is set at 1) but is the pigtail clean and do you have a low pressure (0-3psi or 0-5psi) gage so you can see the actual pressure? When I originally set my pressuretrol at its lowest setting it should have cut out at 1.5psi but it was allowing the boiler to still reach 3psi... The presuretrols aren't that accurate but there are ways to fiddle with them. I am saying this because it sounds like you are only having the issue when pressure could be too high. I used to have the same issue on a small radiator that was close to my boiler until I made sure I never built any significant pressure .

Grallert

I would check to make sure the piping to that rad is pitched correctly my guess is it is not. Also see if it is insulated.A long run uninsulated can make a lot of liquid water.

tim smith

If you had work done on the near boiler piping, did they skim the boiler afterwards. You mentioned that you get fair amount of fluctuation in sight glass, this could be the issue?

neilc

Ptrol looks good on that face, what about the inside dial?
I see 2 gages,
the blurry one below, that doesn't look like it's on zero, or 1.5 or 2, it looks, UP,
and what's the one beside the Ptrol tell you when the boiler is firing a bit?
one more thing you may try,
get a real slow vent on the noisey rad, if some vent too fast, they hold the condensate against the steam coming in, and Bang , bang, hiss , hiss, spitt, spit,

EBEBRATT-Ed

@tsayles50

To lift the radiator, use a crowbar or a scrap of 2x4. Use a wood block for a fulcrum. If you have someone who can put shims under the radiator feet, it would be easier. Just lift one end at a time. Keep the radiator pitched towards the valve. Check the piping in the basement near this radiator for the correct pitch. And only lift the radiator a little at a time. About 1/4" at a time until you get the correct pitch.

Just remember every drop of steam that leaves the boiler will change to water and has to flow back to the boiler return by gravity.

tsayles50

This has all been really helpful. I’ll try to answer everything. 

@dabrakeman yesterday I intentionally did the 2 degree recovery and it didn’t spit steam. Of course when I try to figure out what’s going on it doesn’t do the thing I want to fix. This radiator is far from my boiler but I think the pressure during the two degree recovery may be a problem.

@Grallert I do not know is it’s insulated. It’s in the guts of the house that I don’t have access to it. Regarding pitch, I agree that’s the most likely problem after talking with everyone here. 

@tim smith yes the guy who did the work skimmed. 

@neilc will work in the slow vent. This radiator is already the last to heat up with varivalve vent wide open. 

@EBEBRATT-Ed thank you for saying how to lift the radiator.

again thanks to everyone for the advice and education. 

ChrisJ

We really need some good pictures of the boiler and it's piping. The more pictures you can give us the better we can help.


How is your main venting?

My gut tells me that vent is too fast, even all the way down for that size radiator unless your pressure is very low.

I'd start with a Gorton #5 honestly. The reason that radiator is heating slow is likely because others are also venting too fast. If it was mine I'd probably buy a mixture of Gorton #5's and 6's depending on the location of the radiator and then adjust up or down from there. Use the 5's closer to the boiler and 6's further.

The Gorton and MOM numbers work like this :

4 very slow
5 decent
6 fast
C really fast
D ridiculous. I think this is about where your current vents fall honestly.

In order for everything to work right you need the mains vented very fast and you need the radiators vented as fast as you can, without them stealing and hogging all of the steam. You need it just right so it goes out to all of them at about the same speed. If you go too slow you'll build excess pressure but too fast and radiators start to hog all of the steam.

neilc

I too am going to question your main venting,
If mains are not adequate, then the radiators have to do all the work, and hiss,
you say this noisy one is also last to heat,
if you have these vents on all your rads, these vents being known to be too fast even when closed down, and the other rads are more open, possibly the other rads are venting too fast also, and cheating steam from this last one,
Vent your mains FAST, and vent your rads SLOW

tsayles50

@ChrisJ @neilc

These are the air vents that got installed after the work was done, I’m not worried about them this guy knows what he’s doing.

I found a chart on placement of the gortons, https://www.nyrpcorp.com/content/Images/uploaded/Gorton%20Air%20Valves/Gorton%20Air%20Valve%20Chart.pdf

it definitely makes sense and I’ll be implementing it. 

-Tim

neilc

looks like you have main venting

BobC

Make a list of your radiators and the vent type and number it has (Gorton #5) and also the position on the main. The first radiator on main # 1 would be 1-1 while the 3rd radiator on main #2 would be 2-3, this will let us see where this radiator is on your system.

A system has to be balanced so steam gets to each radiator at about the same time, This is why the main vents are fast compared to individual radiator vents. In general you want to vent radiators slowly to start and then rise the venting rate on those radiators that to slow to heat.

Bob

tsayles50

@ChrisJ thank you so much for the Groton recommendation. I put them in my colder rooms (that bathroom included) and they all warmed up together.

-Tim