Water flowing wrong way through CH system.

[macaque]

I've just had a new boiler installed to replace a worn out unit. During the installation the engineer added TRVs to most of my radiators.

A new pump was installed directly above the new boiler connected to its outlet. This pump is connected the right way round but the water seems to flow backwards through the system as though the pipes are crossed from that point on.

The upper pipe to the hot water tank is always hotter than the lower pipe, which leads directly to the motorised valve. The radiators seem to heat up from back to front. It seems the motorised valve is now at the end of the pipework rather than the beginning.

So hot water is flowing through the pipework, does it matter that it's going the wrong way?

I've yet to agree that the system has been installed correctly and pay the balance owed. Should I?

 

[Armo74]

The top connection to the cylinder should be hotter than the bottom one.
The motorised valve should ideally be on the flow from the boiler.
Some photos of the pipework configuration would help.
What type of TRV's were installed?
Have any other pipework alterations been made?

 

[Agile]

So how are you deciding which is your "right way"?

How are you knowing which is the "back" and the "front" of your rads?

Why are you withholding payment for the new boiler installation? Do you really think that is going to encourage anyone to help you with your apparent misunderstanding of how heating systems work?

Tony

 

[TCCHeating]

If the flow and return on the boiler are piped up correctly. Ie: is the flow pipe from the boiler the first to get hot on initial startup. And if your system is working properly. Then pay the installer!

Ps: it doesn't matter which way the cylinder is piped up. Flow can be connected to either the top or bottom connection of the coil. And all modern trvs are bi directional as well!

 

[macaque]

Thanks Armo74 & TCCHeating for your helpful answers.

I'll try to upload some photos in the coming days but I've got a busy week ahead of me.

The installer(s) made some basic mistakes, which have been corrected and the 1-day job stretched to 4 days - two of those days I was left without proper heating. All seems well now but my confidence in the company took a bit of a hit during those days.

Glad to hear that modern TRVs are bidirectional because I read on other forums that flow direction can be an issue with these. Since I posted my questions I have seen a schematic (several actually) where the flow through the HW cylinder coil was from top to bottom, which I was surprised to learn.

There have been no other alterations to the pipework - as far as I know. The job was completed by two installers (and one electrician) and they gave different answer to my questions. One said that there were two pumps in my old system, one within the boiler casing (a Servowarm Elite 21) and one under the floorboards about 2ft from the motorised valve.

The second installer, who finished the job on the last day, left a message to say that my motorised valve was faulty and he left the actuator off but I've watched it go though the motions correctly several times - in response to the programmer - and reattached it seems to work fine.


I am worried about the position of the feed and expansion pipe (I think they might be one and the same?) in the system because at a previous property there was a problem where the pump used to push hot water into the feed tank when everything was up to temperature. That problem was fixed by moving the pipe to another part of the circuit.

I'll be speaking to the installation company on Monday and your advice will be a great help in that conversation.

Cheers!