This morning they were recognised for their bravery and preservation of life.
But Mr Lemmens said it was all part of the job.
"It needed to be done, otherwise it could have been a lot worse for the people inside.
"I don't think it was a scary moment...we just knew that we had to do something."
A fire crew arrived at the house five minutes later and the fire was isolated to the kitchen area.
Mr Lemmens was surprised the two adults and three children, including a baby, escaped without injuries.
"With the amount of smoke there was, we were expecting some smoke inhalation at least. They were quite lucky."
Spokesman for St John Robbie Walker said: "The crew have done a great job and I'm sure avoided a worse outcome for the very lucky family."
Mr Lemmens agreed and said: "If we hadn't been driving past I guess the fire would have spread, and either woken someone up with a burn or smoke inhalation, or possibly death if they didn't wake up".
"We'd happily do it again."
St John Annual Appeal (6-12 April)
• For the appeal this year St John has the aim of raising $2.4m to buy 12 new ambulances.
• A fully equipped new ambulance costs $200,000 and it costs $1 million to fully equip and crew an ambulance every year.
You can donate by:
- Looking out for collectors shaking buckets around the country
- By donating at any ASB branch
- Calling 0800 ST JOHN (0800 785 646).
- Or to donate online visit: www.stjohnappeal.org.nz