Can I use Parkray now old backboiler empty

[spellcaster]

Hello its my first time on here and I am hoping to get an answer to my query as when i ask people some say yes some say no. So here is my setup. When i moved in my house it had a parkray with back boiler to heat the water for baths and also the radiators. There was a water pump upstairs which used to ciculate this water. I have since had a gas combi boiler put in upstairs and the old backboiler behind the fire has been disconnected from a water supply pipe and it has been drained of water. As the backboiler behind the parkray will never be used again I do not mind if it cracks etc. Basically I would like to know if I set a fire in the parkray what ever this old back boiler thing is, will it explode? or can I use the parkray safely.

[spellcaster]

Hello AJS Heating,

Thanks for your reply.
I have no idea if the pipes have been capped as the pipes are in- accessible behind parkray. there is a drain tap for the back boiler which comes out at the side of the fireplace. There is deffinetly no water in it but if I left the drain tap in the open position would this suffice to stop excessive heat build up. If the pipes are capped whats the worst that can happen to the boiler? or the parkray, chimeny etc

Carl