Hi, new member and in need of help with y plan system.

[ckgreenall]

Hello one and all, I have often looked at this place for hints and tips but am really struggling now. We recently had a new boiler and radiators fitted to our y-plan open vent system. The new boiler is an Ideal logic plus heat 30. Our system has a sunvic time clock, Honeywell stats and a 3 port mid position valve.

In a nut shell, the boiler is reporting a no flow error which is driving us mad. The boiler initially fires up, runs for a couple of minutes and then shuts down with the error. It does the same on both CH an HW setting. We have had both the CH and HW red hot on the odd occasion but once the system comes to rest, the next time we get the issue.

At the moment we cant get any HW and minimal CH. the one thing I will say is that the return pipe only ever gets warm at best which would suggest we do have a flow issue, but we can't work out why.

During the course of investigation we have put in a new pump, auto air vents, air separator and even had the pump wired direct to a plug to keep it running but still get the no flow error.

My plumber is totally out of ideas, any suggestions?

Many thanks,

Chris

 

[AWheating]

has the wiring been checked against the boiler manufactures instructions? has the flow and return pipework been checked for blockages? are the isolators full open/not blocked at the boiler? are the flow and returns crossed?

 

[stratplus]

Has the pump been fitted upside down? I had this problem once with boiler cutting out (open vent thermal store) and pump was upside down.

 

[stratplus]

Also check the pump valves are open.

 

[chris watkins]

That is a very big boiler how big is your house & when the boiler was installed was a filter / magnetic clean installed before the boiler ?

 

[ckgreenall]

All, thanks for your replies. In answer, the flow and return are the right way round. When the boiler fires we get very hot on the flow right up to the airing cupboard, through the pump and the 3 position valve, into the cylinder and through the flow to the rads. At very best we only get luke warm on the return from the rads and the return out the bottom of the cylinder. The pump whilst upside down is installed that way as it is on a downward flow pipe (if that makes sense?).

Re size of house, we are a 4 bed detached with double integral garage. 14 rads including towel rails and a hot water cylinder. Pipe run from boiler which is in the garage to the airing cupboard which is upstairs in mid of house is around 10 meters.

Re the wiring, pump is wired direct to boiler as Ideal state it should be.

All valves checked and double checked, in fact if we are getting a call for heat on the boiler if I half close one of the valves just above the boiler you can hear the water rushing past, so I know we are getting flow of some sort.

Finally, we do have a TF1 filter just above the boiler on the return and this has been removed and put back in to ensure it wasn't the cause of the poor flow.

Thanks again for all your replies.

Chris

 

[ckgreenall]

Just something else to add having just been upstairs monitoring the pump etc in the airing cupboard, when the pump stops we get a gurgling type sound along with water being spat out of the vent into the header tank. Should it be doing this or could this be linked to the problem?

Cheers,

Chris

 

[chris watkins]

No, water should not be coming out of the open vent, as this adds oxygen to the water & increases corrosion, it is most likely due to the pump / pipework not being positioned correctly, although the modern boilers have such small water ways & therefore very high resistant's that this lead to this as well, especially when the system stops & starts. It sounds as though it is a circulation problem with such a big boiler it will need a high water flow rate to carry the heat way otherwise boiler reads the rise in temp & shuts down (21.5L/M). As long as you are sure that no muck has got into the new boiler I would be looking at the pipework around the pump / C/F & open vent position. What size pump & pipe work have you got between the boiler & pump position?

 

[ckgreenall]

Hi Chris, thanks for the reply. We have 22mm pipe from the boiler to the pump and then onwards into the system/s. It is also 22mm on the returns. We then have 15mm to all the rads.

I am beginning to wonder if there is a blockage on the return between where the CH/HW returns join together and the boiler as we seem to have a common flow problem. I think the next course of action is to replace that run of pipe and see if it gets any better.

Chris

 

[TBServices]

I've had this error on the last heat only logic I did, caused by an airlock in the old pipework. Had to put some well positioned air vents in the system to shift it.

Have you considered converting to a sealed system?


Sent from my iPad using Tapatalk HD

 

[chris watkins]

Hi Chris
Instruction suggest 28mm pipe work for the 30 & on a system of that size I would thing your need at least a 15/60 (6Metre head) pump to over come the friction & shift the required water. This is why with these big boys (boilers) it is better to install a low loss header.
CW

 

[ckgreenall]

I've had this error on the last heat only logic I did, caused by an airlock in the old pipework. Had to put some well positioned air vents in the system to shift it.

Have you considered converting to a sealed system?


Sent from my iPad using Tapatalk HD

Hi that has been suggested and I guess is a consideration if we continue to have issues.

 

[ckgreenall]

Hi Chris
Instruction suggest 28mm pipe work for the 30 & on a system of that size I would thing your need at least a 15/60 (6Metre head) pump to over come the friction & shift the required water. This is why with these big boys (boilers) it is better to install a low loss header.
CW

Hi Chris,

We have installed a new Grudfoss Super selectric 15/60 pump as part of our investigations.

What do you mean by a low loss header?

Cheers,

Chris

 

[chris watkins]

Hi Chris
have a look at this post &/or search V.A Heating Ltd they have details.
http://www.ukplumbersforums.co.uk/central-heating-forum/36366-low-loss-header.html

 

[RGII79]

Is your pump on the flow or return pipe is the boiler a heat only or system 30

 

[DirksPlumbing]

Just something else to add having just been upstairs monitoring the pump etc in the airing cupboard, when the pump stops we get a gurgling type sound along with water being spat out of the vent into the header tank. Should it be doing this or could this be linked to the problem?

Sounds incredibly like a high amount of air getting compressed by the pump and releases on stop. Forgot to bleed some radiators? Other than that it sounds first class like an air lock entrapped in a non suitable laid out pipe section.Why did I not read about an ABV by now? Any bypass at all fitted?

 

[RGII79]

Sounds like a problem with the position of pump if your pitching into the expansion tank .might be better to seal the system.

 

[ckgreenall]

Is your pump on the flow or return pipe is the boiler a heat only or system 30

Hi, The pump is on the flow. Pipe leaves the boiler, up to the airing cupboard, into an air seperator (just fitted to see if this would resolve issue), into the pump and then the 3 position valve.

The boiler is a heat only.

Cheers,

Chris

 

[ckgreenall]

Sounds like a problem with the position of pump if your pitching into the expansion tank .might be better to seal the system.

Hi, the pump is after an air seperator and before a 3 position valve.

 

[ckgreenall]

Sounds incredibly like a high amount of air getting compressed by the pump and releases on stop. Forgot to bleed some radiators? Other than that it sounds first class like an air lock entrapped in a non suitable laid out pipe section.Why did I not read about an ABV by now? Any bypass at all fitted?

Hi Dirk, when you say bypass what do you mean?

Thanks,

Chris