Hot water pressure drops when two hot water taps are running - why?

[zammonewfl]

Hi
Could anyone provide me with some possible causes and solutions for a drop in hot water pressure when two hot water taps are being used?
I have a Worcester greenstar 30 cdi condensing system boiler for sealed systems that provides domestic hot water and hot water for underfloor heating. The boiler is also connected to a 280L thermalstore cylinder which can take a secondary heat source like solar if we wanted to install solar thermal at a later stage. Thanks in advance.

 

[ecowarm]

Incoming main supply not up to the job, was it flow and pressure tested prior to fitting Thermalstore? If it was ok and now not it could be a blockage ie a filter or stoptap not turned fully on.
You may need the main supply pipe increasing to 22mm

 

[zammonewfl]

I believe the main supply pipe is 22mm - but how would I check that - sorry I am not a plumber
No pressure testing was done prior to it being fitted to thermalstore

 

[ecowarm]

I believe the main supply pipe is 22mm - but how would I check that - sorry I am not a plumber
No pressure testing was done prior to it being fitted to thermalstore

Try turning the main stopcock on it may not on fully, post a picture of the thermal store if you can

 

[AWheating]

no pressure testing was done, well i would ask your installer why?