Two Radiators Stay Cold - Help!

wanttolearn

I have a problem, I am not sure if there is an easy answer to it:

I have an old house with a single pipe steam radiator system.  I have approx. 20 radiators in total, and all of them work more or less fine, except two radiators in my foyer.  These radiators stay cold most of the time, and only on the very coldest of nights do they get slightly warm.  They never get real hot anymore.

The mystery, however, is that when I moved into my house three years ago, these two radiators were the best performing in the whole house!  They are located very close to the boiler, right of the main steam line, and they used to be the first radiators to get hot, and would get really hot very quickly.

In the three years since I have moved in, I have educated myself on this website, and I have done all the recommended things listed here:  I have put new varivalve vents on all my radiators.  I have added 4 additional main vents (Gortons).  I have insulated all my steam pipes (where possible).  I have turned the pressure on my system way down. etc.etc.etc.

As a result of all these improvements, many radiators that were further away from the boiler and didn't work well at the beginning, now work much better, and overall my system is much better than it was three years ago, WITH THE EXCEPTION of the two radiators in the foyer that no longer get hot!

Over and over again, I have made sure that the valves on both radiators are turned all the way open, and that the varivalve vents are all the way open too. 

So these two radiators have gone from best to worst over the last few years...any possible explanations?  I repeat that both these radiators are very close to the boiler and only a few feet off of the main steam line, but for some reason the steam does not travel the few feet from the main line to these two radiators.

I would appreciate any pointers from any of you.  Thanks!

STEAM DOCTOR

Radiator air vents

Try taking off the varivents from those two radiators and see what happens. Varivents tend to have a short lifespan.

Tim_Hodgson

I agree

with bn, run the pressure up then pull the vents and see if you have any steam pressure in the radiators. If you have no pressure at the vents, then the valves need attention.

If you can't get pressure to build up on the boiler, close 30% of your radiators for the test.



Good luck,

Tim