How Long before Hot

[Diyisfun]

In a typical house, with a new central heating system using a mid position valve & the boiler size has been calculated as being of the correct size. How long would it be expected to take to heat the hot water supply to approx 60 degrees, with the central heating system has not been satisfied.

Whilst make models tank capacity etc are all necessary to make an exact calculation, you plumbers must know the rough answer to this question assuming all plumbing lagging etc is to the latest / highest specs.

The reason for the question is that my system will talk many many hours to heat a tank of water (sufficient for a non pumped shower) unless I turn the room stat down

 

[croydoncorgi]

HW cylinder should recover in 30 to 45 minutes, according to size of coil, volume, etc.
If it's taking hours,
either your boiler's too small
or your 3-port valve is stuck
or the control wiring is incorrect
or the boiler thermostat is set too low.

Valve problem is my favourite, based on limited info. Is this a new or long-standing problem?

 

[Diyisfun]

The system was install 10months ago. I have every confidence in the wiring & boiler size as the persons who installed are 'Heat team' and related to my builder who I have know for 20 years. The only reason for asking the question was that I had wired my previous system in my previous house & wired it in such a way that hot water was always satisfied first. The system worked well & I was questioning if the Y system had a flaw in it, ie slow to heat up. I had thought it might be related to pump speed and did increase that from 2 to 3.

Is it easy to check the valve?

The whole system is fitted in the loft so its quite easy to access (although cold)

 

[ChrisR]

How long does it take the HW to heat of the CH is off? What size is the primary pipe to the HW cyl, how long is it and does it have a gate valve or similar ?

Have you checked there isn't an air lock in the primaries to the HW cyl?

 

[Diyisfun]

During the summer months there was no problem with hot water & pump speed was 1 then.
The pipework is 22mm, have not seen a gate valve, should there be one.

 

[ChrisR]

Have you checked there isn't an air lock in the primaries to the HW cyl?

 

[Diyisfun]

ChrisR Posted: Thu Jan 06, 2005 2:44 pm Post Subject:
Have you checked there isn't an air lock in the primaries to the HW cyl?

Chris..how, please?