New car broken down - can it be replaced?

[nonewcar]

I'd like to know if I refund or replacement for a new car.

I've bought a brand new Hyundai i20 from a Hyundai dealership, using my existing car for a scrappage discount.

I collected the new car this Monday. The next day (yesterday) it broke down and wouldn't start.

I had to call the RAC and they spotted that a radiator hose was disconnected, all the coolant had leaked from the car and there was a possibility the head-gasket had blown as a result of over-heating. If this is the case, they reckon the car will need a new engine.

They towed it back to the dealership who are 'looking into the problem'.

Clearly this is not the experience I expect from buying a brand new car, and I'm concerned that any repairs, or even a replacement engine may not bring peace of mind about the reliability.

Assuming this whole situation was a result of a fault not spotted by the dealers before they handed over the car (and I can't see how it can be anything else - the car broke down within 24 hours of me getting it), am I within my rights to demand a replacement or a refund?

[happywriter]

Clearly this is not the experience to expect from buying a brand new car, and I'm concerned don't expect that a blown head gasket would completely wreck any engine, which in any case is only a possibility.
Many new cars are not driven much before their purchase so that they don't get to a normal temperature. Without the normal temperature pressure will not be in the cooling system. So, the problem should not have happened, but it is the kind of mistake which could get through pre-delivery checks easily.
The dealer should be able to fix that problem easily.