It's hard to say
In the Wayfinder's Guide to Eberron, the specific subraces have guidance on build and weight difference. That being said, only the Juggernaut subrace lists a weight ("up to 450 pounds") out of the three subraces provided in the book. The Skirmisher mentions that they are "lean and designed for speed."
The only other weight references I could find came from previous editions in the form of the 4e Eberron Player's Guide and the random height/weight tables from 3.5e's Eberron Campaign Setting. The 4e sources mentions an average weight of 270-300 lbs. and the tables from 3.5e can generate a weight between 272 lbs. and 318 lbs.
With the release of Eberron: Rising From the Last War, we have an official weight/height generation for 5e Warforged that is the same as the 3.5e one. That being said, they also removed the subraces for Warforged in this publication so there sadly isn't more clarification on this.