Weil Mclain Ultra 155 leak

hcpatel78

Hi just try to figure out why there is constantly leak from my boiler. There is small temperature/pressure check valve and it's constantly leak in my boiler. Up on further investigation I found out expansion tank was failed. Replaced that and the leak is still there from the check valve. Please see attached pictures. I need help to start this boiler back. This boiler is equiped with indirect DHW. 

nicholas bonham-carter

There may be a leak between the fresh water, and the indirect coil.
There should be a valve to close off the water entering the indirect. Close that off and see if the leak stops from the pressure relief valve. The only cure may be a replacement indirect tank.—NBC

Ironman

That looks like a manual bleed valve. If tightening it won't stop it from leaking, then replace it.

HVACNUT

Thats the adapter for the temperature probe on the tridicator gauge. 
The gauge has separate probes for temperature and pressure. Looks like the pressure side is bad as well.
Look in the manual for replacement parts and order a new gauge. 
In the meantime you can remove the adapter and install a 3/8 black plug.
You need to drop the pressure first of course. 

hcpatel78

Thank you all. I have ordered eplacement part and I will report back with results.
Thanks again.
Hiren

hcpatel78

I replaced the valve and leak stopped. But boiler is locked out after few hours with maintenance required message displaying on panel. This unit never been serviced since last 6 to 8 years.

HVACNUT

First, do not throw away the probe adapter. You'll need it when the new part comes.
The maintenance reminder can be reset but it definitely needs to be done asap. Make sure they're familiar with the Ultra gas and to bring an Ultra maintenance kit so it can be cleaned properly. 
The hight temp lockout is because there's no water moving through the boiler. Its probably air locked from the leak. There should be an automatic feed valve with a manual valve before that. Make sure the valve is open. You might need to purge through the boiler. 
Post some pics from about 10 feet away if you can't get the water flowing and we'll try to walk you through it. 

hcpatel78

Ok thank you. It makes sense.
I spoke with tech support and diagnose further with contractor menu. It found out that priority 1 is domestic indirect water heating tank and that circulator is scorching hot. Looks like that is shot.
Rep recommended to replace couple of circulator. One for DHW and another for primary loop.
I am going to replace both and let's see what happens, also i will purge as you suggested.

I will report it here.
Thank you for the guidance.
Hiren

HVACNUT

Purge first. The circs might be ok.

hcpatel78

Got it. Thank you for your advise.
Hiren

hcpatel78

I purge the system and started up.
The strange thing is indirect tank was continuously making gargling noise during that purge. Somehow the pressure gage on the boiler unit wasn't showing any pressure reading. It was stuck at zero. That seems doubtful to me.
Thank you,
Hiren Patel

HVACNUT

You might need to purge all the loops.
I noticed the pressure was at zero. The tridicator has two leads. One for temperature and one for pressure. So the replacement you ordered will rectify that as well.

JohnNY

Hiren, all of this seems new to you. You should really have a qualified service technician go over this system and get it running correctly. You're going to spend more money in stuff you don't need than if you just let someone set it up right one time, safely.

hcpatel78

Thank you all
System running well without any problem.
Hiren

MJV

Hi - sorry to revive an old thread but I had the same pressure sensor line break on my Ultra 155. I replaced the gauge with a new factory part and threaded in the new pressure sensor. I fired up the boiler by requesting domestic hot water and saw that the temperature gauge rise but the pressure sensor remained reading zero. Is there anything I need to do to get the pressure sensor seated and reading properly? it's not leaking at the sensor but the copper tube coming out of the sensor seems a little loose. Thanks!

HVACNUT

The capillary is loose around the sensor nut? Like you can wiggle it in and out? And it's not leaking? 
Did you use tephlon tape or compound or both?
Try it again. Make sure there's no blockage in the bung, and only use a light coat of compound. 
The tridicator with dual sensors has always been problematic. On the series 4 they switched to a standard tridicator that pipes in on the primary manifold. 

Tim_D

The maintenance reminder came up because the control does not properly store the installation and last maintenance dates once powered down. Its a known issue. Just restore the dates and reset the maintenance reminder. If it has been 6 years or more, have it serviced.