Document and Entity Information	9 Months Ended
	Sep. 28, 2014	Oct. 31, 2014 Class A common stock	Oct. 31, 2014 Class B common stock
Entity Registrant Name	WATTS WATER TECHNOLOGIES INC
Entity Central Index Key	0000795403
Document Type	10-Q
Document Period End Date	Sep. 28, 2014
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		28,650,542	6,479,290
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q3