What's this all about

[Timme]

I am trying to understand my heating system 

I have an air source heat pump supplying 10 underfloor heating zones downstairs with 17 circuits and 3 radiators upstairs 

I have had it serviced recently and was made aware that the underfloor pipe circuits may have dirt and debris in them 

I am pretty handy and want to flush out these circuits and clean the flow meter tubes

I am curious to understand why I have this current set up on the manifold whereby the actuators are on the top and the flow meters on the bottom, I was of the understanding that this should be the other way around to prevent air locks in the system 

The current manifold was installed in 2018 and doesn't look to have an easy way of adjusting the flow meter setting 

I have looked on line for set up instructions/commissioning but can't find any 

Should i replace this manifold for one that is more user friendly 

And Is there such a thing as a manifold that has auto balancing capability 

Any advice would be greatly received 

 

Edited February 12 by Timme

[ProDave]

A lot of manifolds similar to that one can be assembled either way, with the flow and return as you have them or the other way up.  Neither is right or wrong.

 

What you have is dirty water, no doubt from being the same water that circulates through the radiators and almost certainly lack of inhibitor.

 

It needs a complete drain down and flush and re filling with clean water and inhibitor mix, and fitting a magnaclean in the pipework would also be a good idea.

 

Not sure if you will succeed in cleaning those flow meters so you can see them again or if they will need replacing.  They are not a type I have seen before.

[Timme]

Thanks for your reply 

Are you able to recommend a good quality reliable manifold make 

My set up consists of 2 x 9 port units coupled together a total of 17 working circuits 

I have heatmiser actuators, would these be a straightforward swap over onto a new replacement manifold 

[Alan Ambrose]

>>> I have heatmiser actuators, would these be a straightforward swap over onto a new replacement manifold

>>> Should i replace this manifold for one that is more user friendly

 

Not sure you need to throw the baby out  - all the manifolds look pretty much like that anyway. 

 

Start by flushing etc as @ProDave said and replace the flow meters if they can't be cleaned.

 

>>> And Is there such a thing as a manifold that has auto balancing capability

 

Salus has some 'auto-balancing' actuators. They get mixed reviews. Search hear on t' 'ub.

[Nickfromwales]

11 hours ago, Timme said:

Any advice would be greatly received

Hi.

Is the system working atm, and can you upload pics of the 2nd manifold please?

 

First issue is they have plumbed the manifold arrangements upside down, as the pump should not be facing down and the blending valve should be below it. Looks like they just tossed away the instruction book and just bolted it together as they saw 'fit'....

 

The flow gauges go on the flow rail, which they have at the bottom, which is wrong, but the issue is to rectify this it all needs swapping around the right way and then the flow and return pipework reconfigured accordingly. About a day per setup should suffice.

 

I'd recommend doing this when the weather is nice, and when the manifold rails are off and the loops open ended, you can then flush these out with cold mains water for free. The black crud (ferrous oxide aka 'rust') will not clean off very well, but don't be too panicked as the water is probably quite clean and the black coating on the flow gauges makes it look like the water is like engine oil; I'd bet it isn't  

 

So, is this actually working atm, eg non emergency 'shituation'?

[Timme]

Thanks for your reply 

The whole system is working but the floors in some of the rooms do not heat up to the thermostat set temperatures hence I am looking at flushing the system, changing the manifold set up, changing the thermostats to digital rather than the dial type

We have had Mitsubishi out last week to service the system (ASHP)

£300 of money wasted, am now looking for local company for the next years service 

The system works OK when the outside temperatures are not too low but as soon as the colder weather comes the heat pump struggles to get the rooms warm