Fears over a deadly gas that put her son in hospital have meant a mother has been unable to switch on her heating as temperatures plummeted this week.

Engineers have disconnected Kirstein Mann’s gas boiler after six-year-old Aaden-James was taken to A&E with headaches, dizziness, lethargy and vomiting.

After being kept in overnight at Medway Maritime Hospital, blood tests revealed that he was suffering from the “toxic effect of carbon monoxide”, according to his discharge notes.

Mother-of-two Mrs Mann, 40, has been told by mhs homes, which owns her house in Holly Road, Strood, that her central heating boiler is not to blame and that there were no fumes coming from the appliance.

But the housing association's contractor Swale Heating, which carried out tests, rated emissions of carbon monoxide and carbon dioxide “high” and a notice has been put on the boiler saying: “Warning Do Not Use Appliance”.

Mrs Mann became concerned after Aaden-James came into her bedroom early on Sunday, February 7, and was sick.

As the day wore on he became more nauseous and complained of being sleepy and dizzy.

She said: “By the afternoon, he was getting worse, so I phoned MedOCC (Medway On Call Care) and they told me to get him to hospital.”

After a blood test, he was admitted to a ward and after another sample it was decided that he needed to stay overnight.

She said: “He was very poorly. He’s normally a healthy boy.

“I should have put two and two together because weeks beforehand I had gone to the doctor because I was waking up with headaches and was dizzy throughout the day.”

"Since it has been turned off we have felt fine. I just wish for my own peace of mind they would replace it" - Kirstein Mann

Mrs Mann’s other son, Kane, 19, called an emergency gas helpline and the appliance was turned off for safety reasons.

Mrs Mann has lived at the house for three years and never had a problem with the appliance, but in recent weeks she noticed beeping coming from it.

An engineer discovered a faulty valve which did need repairing, but a spokesman for mhs homes said the boiler was relatively new, had an up-to-date gas safety certificate and did not need replacing.

The housing society has loaned her fan heaters, but she said in just 10 days she has notched up £85 on her energy bills.

She said: “Since it has been turned off we have felt fine.

“I just wish for my own peace of mind they would replace it.

“In the grand scale of things, it’s not much to ask.”

Steve Stratford, mhs investment manager, said: “The safety of our customers is our primary concern and we have been in contact with Mrs Mann regarding her inquiry.

“The boiler has been tested by an independent consultant, Gas Contract Services, on two occasions and there are no fumes leaking into the property.

“The boiler was shut down as a precautionary measure by Southern Gas Networks after Mrs Mann reported her concerns to them, which is standard procedure for a suspected leak of fumes.

“Swale Heating has made an appointment with Mrs Mann to carry out a routine repair related to emissions outside of the home, provide a new gas safety certificate and recommission the boiler.

“The boiler was installed in 2012 and does not need replacing.”