Low pressure in shower since weekend

[browndog289]

Hello,

We have the following set up in our house:

Boiler
Immersion Tank
Grundfos UPS 15-50 Pump
Honeywell V4037 Valve

We have a mixer tap in the bath which supplies the shower.
Usually the pressure in the shower is good (not quite power shower pressure but not too bad for a mixer tap). However a few weeks back with just the hot water tap on the water had barely enough pressure to trickle out of the shower. This seemed to have solved itself the next morning.

However this weekend the same thing happened and we could only get a trickle out of the shower on hot (cold pressure is fine). I tried changing the pipe from the mixer to the shower head and it improved things a little so we can have showers again. However the pressure is still very low compared to what it was previously.

We have checked washing machines / dishwashers, taps, outside taps & hoses for any leaks and to make sure they were not on but they were all off.

I'm the first to admit that I can only do the basics with plumbing so can anyone tell me what I need to check to solve this?

Thanks

 

[seco services]

if its coming and going poss getting airlock in the hot side.

 

[browndog289]

Thanks for your reply.
Any tips on how I can try and free the airlock?

 

[seco services]

is the cold mains or from a tank in loft?

 

[browndog289]

We have 2 tanks in the loft a round one and a rectangular one - not sure if that answers your question or not!

 

[seco services]

no it can still be either mains or tank fed.

try it and see.
if you can block the spout on the tap open the hot tap and open the cold the cold will push the hot backwards if mains pressure and push the airlock out, try this for a min or two. then try the hot.