System Boiler Need Bypass?

[Chrisdorsett]

Hi,I'm new to the forum so hi to all. I've searched but can't find a definite answer to this.I have an old Ultra DV50 boiler which has an integral bypass fitted. I am having 2 zones installed on the heating side with zone valves that will close when each zone reaches the correct temperature. My question is do I need to have an external bypass valve fitted between the flow and return pipes or will the integral one be sufficient?Many thanks,Chris

 

[stevetheplumber]

i dont know the boiler but if it has a full system bypass internal then no

 

[ecowarm]

Welcome to the forum Chris, If the zone valves are wired correctly the boiler will not fire when the zones are satisfied so no need to have an extra by pass

 

[Chrisdorsett]

Thanks for the replies. So when the zone valves shut will the boiler overun through the bypass valve until it is cool enough to shut off?

 

[That Extra Mile]

The internal bypass will allow water to continue to circulate and prevent excessive heat build up in the exchange.