Their armor level is very low when using the healing signet. So the best option is to try to cause maximum damage at that point. Usually easy to cause a lot more damage than the signet heals. You can try to prevent the signet usage using ele or mesmer skills, but I think it is better to just beat a warrior character to a pulp while he is using the signet.
People playing warriors should also take that into account. I get real pissed when I am playing a monk and there is a warrior that keeps on using his healing signet when his health is still fairly high (and while being beaten on by a lot of enemies while tanking) and then blames me when he dies practically instantly.
People playing warriors should also take that into account. I get real pissed when I am playing a monk and there is a warrior that keeps on using his healing signet when his health is still fairly high (and while being beaten on by a lot of enemies while tanking) and then blames me when he dies practically instantly.