Dunkirk boiler pwb-5d , and an aquastat l8148e.
Replyed
After checking to be sure no other control is wired into the aquastat and has failed replace the aquastat contro always double check all circuits

Don't know how to reply to the answer so I am doing it like this ,
So can I safely run the 24 volts directly to the module,it turns on the boiler ?or can it cause damage?
Or must I replace it?
What can cause just 3 volts on the b1 an b2? What is the volts suppose to read ?
Can it be a bad relay?
Can I just replace the relay?
Thank you

so can i safely run the 24 volts directly to the module

It is not safe to run the boiler without the aquastat controler!!

If the aquastat is defective it has to be replaced and professionally adjusted for safety and proper operation.

Here is a copy of your aquastat wiring and install instructions. See FIG. 13

http://customer.honeywell.com/techlit/pdf/60-0000s/60-2278.pdf


If you do not know what you are doing I recommend you Call for ON SITE service. Boilers can be dangerous to work on.