Disappointed in hot water supply

al shookup · Dec 11, 2021

I had a new central heating system installed a year ago but whilst the radiators seem okay I am not happy with the hot water supply. I live in a bungalow so the boiler is on the same level as the radiators. When I turn on the hot water tap I have to run off what seems like at least a gallon of water before any warmth is felt. Is there an adjustment of any kind on the boiler (Greenstar CDi Classic) that can improve the system please?
thanks in anticipation

Scott_D · Dec 11, 2021

Turn off eco mode to preheat the hot water
Assuming it’s a combi

steadyon · Dec 11, 2021

1. What sort of boiler did you have before? The CDi is a combi boiler so no hot water cylinder.
2. Did you have a hot water cylinder before?
3. How far is it from the boiler to the hot water outlet(s)

Almost certainly the wait for hot water is caused by:
a. The need to push out cooled water from the length of pipe connecting each hot outlet to the boiler.
b. Plus the time required for the boiler heat the water in the primary side of the secondary heat exchanger.

There is no boiler adjustment to reduce the wait time.

ShaunCorbs · Dec 11, 2021

It’s normally to run off a bit of hot water due to that water in the pipe going cold since you last used the same tap

Ric2013 · Dec 11, 2021

You could reduce the diameter of the hot water pipe between the boiler and your tap(s) to reduce the cold water content if this was not already done when the boiler was replaced?

From another angle, the benefits of this product are being massively overstated. But might also help solve your problem. Yet to fit one myself. They seem expensive, but, if they work...