Question about pressure gauge

wheel

Hello I have a couple of questions. If I install a 0 - 5 lb pressure gauge after the pigtail that runs to pressuretrol, I'm going to install a tee on top of the pigtail, mount the pressuretrol with a close nipple and run a short piece of pipe for the new gauge, will this work? The gauge will read the pressure? I'm having some issues with the pressuretrol not shutting off at the low cut out, .5 and diff of 1. The 0 - 30 boiler gauge is running up to 5 or so lbs and pressuretrol is not shutting it down. I checked everything on the boiler 8for clogging, couldn't find anything major. My system is a one pipe vented by the radiators, new boiler put in 7 years ago. I put some new valves, maid o mist, on all of them. Radiators get nice and hot. I don't know if the pressuretrol is bad or the 0- 30 boiler gauge is bad. I want to have a second lower rated gauge to check and see if pressure is somewhat correct or the boiler gauge is bad. Aiso the 0- 30 gauge is taking 20 min minimum to zero out, is that ok? Sorry for the state of this post, it's all over the place. Thanks for any replies

EdTheHeaterMan

Pressure controls for boilers are not the most accurate devices. The more accurate controls are called vaporstats. As far as pressure gauges are concerned, the 0 to 30 gauge is a code requirement. They are also not the most accurate measuring devices for boilers. That said, you can add a vaporstat and a more accurate pressure gauge in order to dial in the boiler pressure.

https://www.supplyhouse.com/Honeywell-L408J1017-Vaporstat-Controllers-0-psi-to-4-psi
https://www.supplyhouse.com/sh/control/productComparison


By the Way, Is this the same steam boiler that you were talking about 14 years ago?

Jamie Hall

Sounds to me as though something is clogged between the boiler and the pressuretrol and pressure gauge.

EBEBRATT-Ed

Make sure the pigtail and pipe that goes inside the boiler is clear. If it take the 0-30 a long time to go back to 0 when the burner is off it could be a bad gauge.

ethicalpaul

Yes the new gauge will read the pressure it sees

wheel

Thanks to all who answered. I will recheck all parts for any possible issues and repost what happens. Thank you

wheel

ed the heaterman, I went back down and checked the paperwork with the servicing data on it, yes my mistake I read off of the wrong line. It is the same boiler. I guess time is going by way faster then I can remember. It has been a good working system, no pipe knocking since that post. I didn't realize that my posts were under my account name, nice feature not having to search.

SteamingatMohawk

Boring sermon...if you install a low range pressure gauge, provide an isolation valve and do not leave the gauge in service when unattended.

A few years ago I checked into the structural capability of gauges and the general answer is that they are good for 130% of full range. That means if you have a pressure excursion in your boiler above 6.5psig (relief valve is set at 15 psig), there could be a leak or worse.