Flow and return the wrong way around????

[delboyd]

Hello all

I was wondering if somebody could give me some advice on my heating system?
I recently moved into a new (7 year old) house and it has a Potterton Suprima boiler central heating system installed.
Since we moved in the heating has been a nightmare, and to cut a long story short after numerous BG engineers coming round to look at it the final diagnosis is that the flow and return coming from the boiler are the wrong way around and need swapping over.
All I wanted to know is if anybody had ever come across this before?
The heating still works, but takes a long time to heat up the house.

Many thanks in advance

 

[namsag]

YEP its not unusual for them to mixed up . And needs altering for boiler to function correctly

 

[delboyd]

Thanks for the quick reply,

Just out of interest, If this system has been like this since it was built would the previous owners not have noticed? (they had it from new)

Would this problem make my gas bill go up as the boiler is not functioning correctly?

Thanks again

 

[Nige F]

it`s not unusual to be loved by anyone , but when I`m out and about seeing plumbing done ...It`s not unusuall to see me I wanna die (laughing @ the lash ups) ...........any NHBC warantee left

 

[delboyd]

Cheers for the reply and song

We did contact the NHBC but they said that this type of fault (anything with pipes) should have been reported within the first 2 years, is this correct?

 

[fitz1]

aint that convenient. for them.

 

[croydoncorgi]

Be careful to re-confirm the diagnosis.
There are two possible variations:
- the pump is back to front, so that water does indeed flow backwards through the system. If you have a conventional layout, the pipe FROM the boiler should go to the pump, with the 'open vent' and cold feed pipes connected just before the pump. The arrow on the pump body should point AWAY from the boiler. After the pump, there should be one or two motorised valves to control heatflow to the hot water and heating. If the arrow is pointing towards the boiler, the pump isolators need to be closed / the system needs to be drained, and then whole pump disconnected from the pipework and turned 180 degrees, so the arrow points in the right direction.

- the pump may be the RIGHT way round but connected to the wrong pipe coming from the boiler. Ways to confirm this: the boiler will be VERY unhappy, overheating frequently and locking out. When it starts from cold, the RIGHT HAND of the two pipes coming out of the top, left of the boiler will get hot first. This SHOULD be the Return pipe and get warm some time LATER than the lefthand (Flow) pipe. The reason the boiler is unhappy is that the temperature sensors are attached to the lefthand pipe and only see any heat LONG after the boiler has cooked up!!! The easiest way to correct this is usually to swap the pipes over near the boiler.

 

[namsag]

Previous owners may not have noticed all depends if they liked a hot house or what they where used to in previous house.... If boiler was on BG contract before you moved in . There could still be a job history on the engineers lap top from previous owner. Know a few northants engineeers where abouts are you

 

[nickso]

Previous owners may not have noticed all depends if they liked a hot house or what they where used to in previous house.... If boiler was on BG contract before you moved in . There could still be a job history on the engineers lap top from previous owner. Know a few northants engineeers where abouts are you

bg engineers shouldnt be disclosing previous history to new owner.

namsags mates could though

 

[corgiman]

it`s not unusual to be loved by anyone , but when I`m out and about seeing plumbing done ...It`s not unusuall to see me I wanna die (laughing @ the lash ups) ...........any NHBC warantee left

dammit I was going to that joke

 

[Agile]

I was called by Alex to a system fault and found that the G-W boiler had been installed for the last 10 years with the flow and return reversed.

In reality the cast iron boiler will work pretty adequately when its reversed. Not correct though!

Tony

 

[croydoncorgi]

Yes - maybe OK on SOME boilers, eg. those with a stat in a pocket in the heat exchanger body.
But it B well isn't on Suprimas because the sensors (both main thermister and overheat stat) are on what's SUPPOSED to be the Flow pipe. If it isn't - well, you work it out!!!

 

[wobbin]

Hey chaps - could you confirm how the pipework should be on a Potterton Profile 50e boiler too ?

When my boiler is running it's the left hand pipe that gets hot first, and it does seem to cycle a lot more than I thought it would, and the boiler case is very hot.

Regards,
Robin

 

[croydoncorgi]

Profile is same pipe order as Suprima - leftmost is Flow. So your pipe layout is probably correct. (Crossed pipes can occur (eg on a Suprima) because the PREVIOUS boiler was another make (eg. Glowworm Ultimate) which had Flow on the RIGHT.)

How often does it cycle? Tends to happen a bit on older boilers, mostly because the burner is 'all-or-nothing'.

And the front gets quite hot because there's no insulation between the front of the heat exchanger / combustion cover and the front panel. (If it's installed in a cupboard, it must have ventilation to cool the boiler, not for combustion air!)

 

[wobbin]

Thanks for that

I've just timed it - boiler runs for around 3 minutes then off for a couple of minutes. This is with the boiler stat on 3 and with hot water demand (the offspring are hogging the shower !)

I've recently had some overheat problems, caused by airlocks. I found that I could get things going again by opening the drain cock which is on the return side of the boiler pipework, with the hose submerged in 1/3rd of a bucket of water so that air couldn't be drawn in again.

Seems to have settled down now. There was no inhibitor in previously so it may have been a build up of gas rather than air ingress. I've got X400 running round at the moment to help clear up the rubbish that's floating round the system, ready for a draindown and refill with X100 in a fortnight or so. Might even push the boat out and pressure wash the rads

Thanks for your help. This is a great forum.

Kind Regards,
Robin