Katie Haines, 31, of Wokingham, drowned in the bath after breathing in carbon monoxide from a leaking boiler.
A gas engineer had certified the boiler “at risk” a few months previously but it had not been fixed, despite his concerns about ventilation.
The couple had bought a carbon monoxide alarm but had never installed it.
Richard Haines, who found his wife’s body, said: “I knew something was up. We have a cat and the cat was acting really strangely.
“I found Katie in the bath, immersed, overcome by carbon monoxide.”
Mr Haines said he had gone into “auto-pilot” while getting his wife out of the bath and giving her CPR.
Even after 10 minutes in the house, he also had what he described as an “over-critical” level of carbon monoxide in his blood.
Since his wife’s death, he has set up the Katie Haines Memorial Trust charity, having amassed £50k of charitable donations.
The trust intends to promote awareness of the dangers of carbon monoxide to vulnerable groups such as students, holidaymakers and the elderly.
Mr Haines said the charity was a “legacy” for his wife.