Unvented Cylinder, Central Heating and Underfloor Heating

[T786]

Try this... get the instruction manual for your boiler and find out how to get in to the D codes, when you have go to D0 and reduce the output to 24 and see if your rads heat any better, chances are that you will have to upgrade the pump regardless.

Hi I tried this and it made little or no change.

as I said earlier close coupled tees or a low loss header,

Where would I install the low loss header? The cyclinder is approximately 100 sq ft away from the boiler.

The UFH install sounds like a massive lashup as well- take it there's a single loop, no manifold, no bypass?

Where would I install the manifold and thermostat to this now? Next to the boiler or in the UFH room?

 

[picasso]

Its not really a diy project, get your self an experienced heating engineer that has installed llh before.

 

[flameport]

This mess needs to be sorted as a priority.
Live electrical connections exposed.

 

[T786]

This mess needs to be sorted as a priority

I agree, in the current pandemic it is hard to find anyone reliable.

 

[T786]

I have finally managed to get someone who has sorted all the issues and my system is working perfect.

Cold mains increased to 28mm
Y plan heating system changed to S plan with UFH as a separate zone
CH as a separate zone
Separate thermostat for UFH and separate for CH

Did not have to change boiler.

Thanks for everyone's input.

 

[picasso]

No one suggested changing the boiler, was the blue pump changed ?

 

[muggles]

The blue-grey pump would have been supplied with the UFH, and the red one that's connected to the UFH is the original system pump (manufacturing date 2008). Looks like they realised there was a problem when they installed it and swapped them over to try to mask it. Good to hear it's all sorted

 

[T786]

Blue pump was not changed. Red pump got taken off and re installed with venting bottles.

 

[picasso]

If your running a system that size on a 25/60 I doubt it will "working perfect" when all the rads are on at the same time.

 

[T786]

I don't know what you mean when you say 25/60. But the house gets very hot in 10 - 15 mins. The hot water in approximately 20 minutes. The ufh can take a little longer but I imagine that is due the the span of the pipe?

 

[picasso]

25/60 is the size of the pump, your house is 3000 square feet with 11 double rads so I am surprised the pump is powerful enough with the boiler heat ex taking nearly half of the pumps head, if its working ok that's good to hear.