Grants for new boiler

Dee140157

I have read much of this thread with interest as it never occurred to me to look for a grant for central heating. Still not entirely sure if it is possible. Maybe somone can advise?
Situation is this:
B. owns his house. He is on working family tax credit but no disability element.
His mother lives with him. She doesn't own house or pay rent. She is on pension credit and in receipt of attendance allowance, but is not the householder as such.
B has 3 storage heaters, one which does not work, one which is now very inefficient and one small onein bathroom that is sort of ok.
Any chance of a grant would be fabulous. So is it worth applying?