There is a strong nasty smell in the kitchen first thing in the morning, it goes away during the day. But returns in the evening, but its not quite as bad as it is in the morning. We have just moved into the house and we have given it a good clean

Does it smell like someone passed gas (farted)? If so, it could be your water heater. I had the same problem. When everyone in the house would take showers in the morning, it would be the strongest. By the middle of the afternoon, it was gone. At night it would get bad again, because we ran the dishwasher and laundry. Turns out the pipe was leaking and water was stagnant and starting to smell. We called a plumber who came right out and fixed it inexpensively. Hope this helps.

Are you on a septic tank or city sewer" . Sounds like it may be sewer gas. I can answer your question about why it doesn't smell in the day time. Sewer gas raises in the heat of the day so you wouldn't but with nightfall the heat is gone and the gas descends down to where you can snell it.'m going to move your thread up to the Plumbing Page where it will get better attention, Good luck, Tom