Am I within tenant rights to with hold my rent payment?

I have lived in this house for 3 months now and it has come apparent that the landlord is not willing to keep to his responsibility as a landlord as I am now in my 5th week of having no hot water or heat and I have 2 small children. I have taken steps with a company called Warmfront to help repair the boiler through a government grant as I am a single full time mom and cannot physically pay for it myself but until that is done am I within my rights to refuse payment to my landlord?