Facetious..
I'm interested in your source about the tenant having to get three quotes- and only after getting three and choosing the cheapest is the tenant allowed to deduct expenses from the rent.
Furthermore the tenant can only do this after the LL has done nothing within fourteen days.
Where the landlord has been notified in writing of a breach of his obligations and has failed to remedy that breach within
a reasonable time, a tenant is entitled to vacate the property (whether fixed term lease or a Part 4) and a notice of termination giving 28 days to vacate the property, may be given by the tenant.
Alternatively, a tenant wishing to remain in the property, may organise repairs himself. However, the landlord is only liable for the "reasonable costs".
It is not a legal requirement, but,
for the avoidance of any doubt, it is best for a tenant to get at least two (preferably three) quotes for the work/repairs to be carried out, and to select the lowest/cheapest and advise the landlord beforehand, that the cost will be deducted from the rent.
You can read PRTB determinations where the tenant has not been allowed the full cost of repairs/replacement where the landlord has had evidence that the cost was unreasonable.
Furthermore, a tenant could get a "mate" to do some repairs for which the landlord is liable and "up" the price and just issue a receipt/invoice for an inflated value.
Also - if the tenant withholds rent when the LL has breached his obligations then the tenant is also breaching his obligation. What? A tenant is obliged to continue paying rent even if the apartment is uninhabitable due to LL's breach of obligations?
Where a tenant has withheld the payment of rent (i.e. not paying the rent "as it falls due") the tenant is in breach of the tenants obligations. There are many PRTB determinations where a tenant, in trying to get a landlord to effect a landlord's breach of obligations, has withheld rent. However, had the tenant not withheld the rent, he would have been awarded damages in respect of the landlord's breach. Two wrongs don't make a right.
As regards your scenario that if the "apartment is uninhabitable", surely a tenant would issue a Notice of Termination and vacate the property. In the case where a property "suddenly" becomes uninhabitable, it would not be reasonable to expect a tenant to pay rent and no PRTB determination would award damages against the tenant in such a case. A bit of locic must be applied.
So, next time something goes wrong with an appliance I can tell the tenants it may take two weeks to replace or repair -and only after that they can get three quotes before deducting rent.
Sounds great if I was a wicked LL.
A landlord is under an obligation to have repairs effected "within a reasonable time". A good landlord would not wait for the reasonable time to pass before remedying a problem. Different problems can take different amounts of time to rectify. Some problems are obviously more urgent than others. Hence, the law states "a reasonable time" and not a number of days. Would you leave the repair of a burst/leaking pipe for 14 days before commencing repairs? Other cases may require obtaining special parts which may not be immediately available.
Where a cooker is not broken, as is the case with the OP, a landlord should at least respond within 48 hours to a verbal complaint by the tenant - who should always follow up any verbal communication with a formal written complaint. This not only safeguards the tenant in his obligations to notify the landlord of an issue within the property, but can also act as evidence as to when the issue first occurred. This evidence may be vital should a claim be made by the tenant for the landlord's breach of obligations.
You, yourself, may not be a wicked landlord - but there are quite a few out there who do not know their obligations or hope that the tenant does not know the law.