Pupils will not be able to attend classes as normal after the problem came to light on Sunday, January 5, leaving only the main building with heating.
The school did not return in full as expected on Monday, January 6, with only S1-3 accommodated within the heated area.
The issue was not remedied before this time due to the need for parts to be sourced – with the manufacturer not returning to work until Monday.
It is the second time the school boiler has led to disruption following a similar issue in late December.
On Monday, pupils in S4-6 were asked to work at home using the Google Classroom and ACHIEVE online platforms to continue their preparations for upcoming prelim exams.
Content was posted on the forums by teachers when they returned to classrooms on Monday.
A further update was provided following the conclusion of the first day back at school, detailing temporary arrangements to allow as many pupils as possible to attend classes in person while the heating issue is resolved.
In a letter addressed to parents and carers, head teacher Anne Anderson thanked all for their support during this time.
She said: “I appreciate that it is challenging for pupils but I have been really impressed with how they have managed and the effort they have put into their work.
“I have been provided with an update on the repair required to the boiler. Contractors and engineers have been on site today and arrangements are being made to source the parts required to repair the boiler.
“This hopefully will be a matter of days and we will be back to normal soon. I will, of course, let you know when I know more.
“In the meantime, we have been provided with a number of temporary heaters that we can use in space in the A and B block which will allow us to increase the number of pupils attending each day.”
For the remainder of the school week, pupils in S1-2 will continue to attend classes as normal each day.
Pupils in third year will be able to attend on Wednesday and Friday, and will be asked to complete work on Google Classroom when not in school.
Fourth year students can attend on Tuesday and Thursday but will be asked to work from home on other days.
Pupils in S5-6 have been told to attend for the double periods at the beginning and end of Wednesday, Thursday and Friday – with work also provided for when they are at home.
Students will be allowed to go home in the middle of the day, with arrangements to be made for those travelling from West Kilbride who may be unable to do so.
North Ayrshire Council has been contacted for comment.