Hot water from new boiler

[peter lanky]

I have recently had a Worcester Bosch 30CDi system boiler installed and am trying to estaimate how much time I should have the boiler on to get a constant supply of hot water.

My previous boiler was an 18kW baxi boiler which I had running for around 90 mins morning and evening on quite a low setting, which gave me adequate hot water for everything for baths showers etc, but probably needed a 1 hour boost when more than 1 person was taking a bath.

Considering the significant extra power of this boiler, I have been running it for 50 mins twice a day with the boiler setting on 5. The digital display on the boiler is showing 55.

However, the water is simply not getting as hot as I feel it should be. What settings and timings should I be using to heat a typical tank up to a temperature where the airing cupboard feels warm when it's opened?

I am not using central heating at the moment.

 

[SimonJohns]

Just leave hot water on constant.

If you cylinder is a well insulated model then it will always keep it warn

 

[Dotty]

What is your cylinder stat set at?

 

[jtsplumbing]

You need to set your cyl stat about 60c Boiler stat 65/70c Boiler with 30Kw should heat your cylinder with in 20mins ! did you have the cylinder replaced for a HE type ?? What was the reason for fitting a larger output boiler ?

 

[Howsie]

Call the plumber who put your new boiler in. He should have taken you through these steps.

 

[peter lanky]

Cylinder stat set at 65.
Reason for having more powerful boiler was installer recommended this because it had a longer guarantee, for not much extra cost.
Cylinder was not changed.

Boiler stat just has a number rather than a temperature.

 

[SimonG]

How old is the cylinder? Might have been better to get same size boiler and spend the extra on a high efficiency cylinder.

As Simon Johns said if you have your cylinder stat set it will knock boiler off when cylinder is warm enough.

 

[ManchesterGas]

Do you have 2 x 2 port valves or 1 x 3 port?

I only ask because a 3 port will only flow 11kw so you would need to have 2 x 2 port valves fitted to take advantage of the higher output boiler.

 

[peter lanky]

I've changed the settings as suggested by jtsplumbing. Seems to be a lot better now.

Manchestergas, I'm afraid I haven't a clue.