The new home has low hot water flow and pressure


New Member
I recently bought a new home from a reputed builder in the UK. The day I went to collect the keys was the day I had access to see what was inside. I noticed that a ThermaQ Evocyl pre-plumbed cylinder was missing from my home. This is against the plan and the "Building Regulations and Construction Notes" they had given.

According to their documentation, it says for 4 and 5 bedroom houses, the heating system shall include a "Boiler Ideal Logic with ThermaQ Evocyl pre-plumbed cylinder". My house is a 4-bedroom house, and it has 3 floors. Recently, we had a scenario where the kitchen tap, first floor bath shower, and top floor tap and shower were all on. Then I noticed the top floor en-suit tap and shower were hardly getting any water.

When asked about this, the builder said they were investigating this. Two days later, they came back and said the drawing they provided was wrong. Which wasn’t making any sense since I can clearly see the water pressure and flow that I get on the top floor is not sufficient.

Do you have any suggestions in this case?

new build inspector

snagging inspections 01788 494400
are you saying you have a combi boiler now , instead of a cylinder ?

is this on the hot side or the cold side or both ?

if thats the case check underside of boiler for the pressure gauge and see what you are getting through

if you have a cylinder the pressure gauge for the hot side will be attached to cylinder somewhere , and can be easily topped up using the filling loop

average is around 1.5 bar , but can vary
NHBC Technical Standards 8.1.3 state minimum dynamic pressure of 1.5 bar is available at the stop valve. Minimum flow rate of 20litres per minute. Flow rate and temperature requirements are noted in NHBC Technical Standards section 8.1.5. Table 4. If you have a combi boiler I would say it will struggle to achieve these flow rates. The standards are free to Download. Speak to a plumbing merchant...they will advise on combi boiler size for your property and compare to that installed.