Issues with new heating zone

John.G

You might close in ABV to 0.45, you should be able to remove/replace the TRV head easily by just unscrewing the knurled nut,just ensure that the TRV is fully opened (setting 5?) in each case. The varying cycling time is puzzling, one might think that it would be a constant 5 minutes or whatever you might note a few of the temperature readings when it next happens.

powerade

Thanks John. It puzzled me also. The other thing that I noticed this morning with both zones was that, on the first cycle upwards, the temperature rapidly climbed back up to 71 degrees and then straight back down again to 59. Then it slowly fell to 54 degrees before cycling upwards again. It was almost as if the water had not cooled down sufficiently when the first upward cycle kicked in. I hope that makes sense.
I'm about to test Zone 1 again with the ABV set at .45. Then I will move on to Zone 2. I will see if there is any change in the boilet behaviour/temperature rate of increase before removing the TRV from the radiator in the room with the digital thermostat for starters.

I Am The Law

I Am The Law wrote: »

Can you confirm that the Flow from and Return to the boiler have not been swapped by mistake when first installed?

Have you done this? ^^

powerade

Not yet as I haven't been able to find the manual today. Also, I have only experienced these issues since the heating was re-configured into two zones. Prior to that it never cycled, to the best of my knowledge, and the rooms appeared to heat uniformly. So, can I clarify if you mean on the original installation of the boiler or if a mix up could have happened when the new pipework for the zones were installed?

powerade

I removed the TRV head on the radiator in the room with the digital thermostat in Zone 1 this evening and, whilst this radiator got really warm, the radiator in the kitchen was tepid so I reconnected the TRV and reset the ABV to .35. That seemed to sort that out.
Prior to that I had the ABV set at .45 but that didn't appear to sort out the cycling and it had no impact on the rate of temperature increase in Zone 2. I then dis-connected the TRV on the radiator in the room with the digital thermostat in Zone 2 but this had no impact. I dis connected a second TRV on the radiator in the bedroom in Zone 2, again no impact.
I then turned both zones on together. The boiler purred along at 65 degrees but the rate of temperature change in Zone 2 was still painfully slow. I keep coming back to this as it seems to me that the cycling of the boiler is not the root cause of the slow temperature increase in Zone 2, I.e. it is slow regardless as to whether the boiler is cycling or not.
I eventually turned Zone 2 off as I was just wasting gas. As soon as I did that the boiler temperature rose to 69 degrees as Zone 1 was still running and the boiler cycled.
I will try the lockshields tomorrow, as Gary suggested, but I am concerned that I might end up unbalancing the system. I will also have a look at the flow and return.
In the meantime I have emailed the plumber who did the work for me as I am conscious that I am taking up a lot of everyone's time, for which I am very grateful. I don't expect to hear back from him but I had to try.

powerade

powerade wrote: »

I removed the TRV head on the radiator in the room with the digital thermostat in Zone 1 this evening and, whilst this radiator got really warm, the radiator in the kitchen was tepid so I reconnected the TRV and reset the ABV to .35. That seemed to sort that out.
Prior to that I had the ABV set at .45 but that didn't appear to sort out the cycling and it had no impact on the rate of temperature increase in Zone 2. I then dis-connected the TRV on the radiator in the room with the digital thermostat in Zone 2 but this had no impact. I dis connected a second TRV on the radiator in the bedroom in Zone 2, again no impact.
I then turned both zones on together. The boiler purred along at 65 degrees but the rate of temperature change in Zone 2 was still painfully slow. I keep coming back to this as it seems to me that the cycling of the boiler is not the root cause of the slow temperature increase in Zone 2, I.e. it is slow regardless as to whether the boiler is cycling or not.
I eventually turned Zone 2 off as I was just wasting gas. As soon as I did that the boiler temperature rose to 69 degrees as Zone 1 was still running and the boiler cycled.
I will try the lockshields tomorrow, as Gary suggested, but I am concerned that I might end up unbalancing the system. I will also have a look at the flow and return.
In the meantime I have emailed the plumber who did the work for me as I am conscious that I am taking up a lot of everyone's time, for which I am very grateful. I don't expect to hear back from him but I had to try.

Sorry, I’m not asking you to go near the lock shields but the heads of the trvs.

If it were me I would like to know how the two zones work with no trvs to prove the heat is getting around correctly and if not why not, once I’m happy the two zones work happily is then add the trvs to see if there slowing things to much causing the boiler to cycle and if so what adjustments can I make with the bypass to help with circulation.

powerade

Sorry Gary, I thought you mentioned in an earlier post to turn the lock shield anti clock wise for half a turn if removing the TRV heads did not improve things. Okay, so I should remove all of the TRV heads in both zones and see what happens. I heard back from the plumber, by the way. As far as he is concerned everything is working 100% perfectly.

powerade

powerade wrote: »

Sorry Gary, I thought you mentioned in an earlier post to turn the lock shield anti clock wise for half a turn if removing the TRV heads did not improve things. Okay, so I should remove all of the TRV heads in both zones and see what happens. I heard back from the plumber, by the way. As far as he is concerned everything is working 100% perfectly.

The boiler should be able to feed both zones happily and when you add trvs any extra restrictions when the trvs are satisfied should be offset with your auto bypass, obviously the question is what is failing you

John.G

There certainly seems to be a circulation problem with zone2, I have only a few suggestions to offer, one is to check that the ABV is connected between the flow and return pipework and the other is to check that the boiler pressure is 1.0 to 1.5 bar when cold.
You also said in another post that the boiler consumed 0.5 of a unit of gas which I assume is 0.5 cu meters in 1/2 an hour, this equates to 5.35 kWh or 10,7 kw/hr which suggests that the boiler is firing at full output for 50% of the time

powerade

So, if I remove all of the TRV's and fire up both zones, would you expect both zones to heat up at more or less the same pace?

powerade

John, the boiler pressure is 1.0 bar when cold and 1.5 bar when the heating is running.I don't quite follow the maths but I was comparing a consumption of 1/2 unit (based on readings from the gas metre) to run two radiators in 30 minutes versus the same consumption to run every radiator in the house for the same time period. I'll get back to you on the ABV.

powerade

I opened every TRV fully and removed the heads from each of the radiators in Zone 2. I turned on both zones and set both digital thermostats to 18 degrees. Zone 1 starting temperature was 14 degrees, zone 2 was 14.4. The boiler temperature was 20 degrees when I turned the heating on at 9:03. The boiler temperature appeared to be very slow to rise, I.e. it took 24 minutes to reach 65 degrees. By 9:31 Zone 1 temperature had increased by .7 of a degree (slow for Zone 1) and Zone 2 had increased by .4 of a degree. At this point I took off the TRV heads on all of the radiators in Zone 1. The ABV is set at .35. By 10:33 Zone 1 had reached 18 degrees so it took 1 1/2 hours to warm up by 4 degrees. I did not observe any cycling but the boiler temperature did fluctuate a bit between 63 and 66 degrees. In that same time period, Zone 2 temperature increased by 2.2 degrees. This is consistent with what I have observed in the past, I.e.it takes Zone 2 roughly twice as long to heat up when both zones are running. The radiator in the kitchen didn't really warm up in Zone 1 which I noticed for the first time last night when I removed the TRV head from the radiator in the room with the digital thermostat in Zone 1.
When demand was satisfied in Zone 1, Zone 2 continued to heat up and it finally reached 18 degrees at 11:24. The boiler cycled when only Zone 1 was running. The first was after 26 minutes of running Zone 1 only. Then there was the rapid climb up to 71 degrees followed by a rapid fall down to 54 degrees and then another cycle up. The rate of temperature change in Zone 2 appeared to be roughly the same, regardless as to whether both zones were running or just Zone 2 on its own. However, the level of cycling was greatly reduced as all four radiators in Zone 2 were running at full blast. If I put the TRV heads back on and turned off the bedroom radiator, I.e. back to the previous configuration, it would cycle a lot more. I really don't know what to do next........

Wearb

@powerade Does any of your rads have cold bottom centres when up to temperature?

powerade

All of the radiators have been bled. The only radiator that is noticeably cooler than the others is the one in the kitchen and that is only since I removed the TRV head from the living room in Zone 1yesterday.

Wearb

powerade wrote: »

All of the radiators have been bled. The only radiator that is noticeably cooler than the others is the one in the kitchen and that is only since I removed the TRV head from the living room in Zone 1yesterday.

Does any of your rads have cold bottom centres when up to temperature?

powerade

I think that they are all colder at the bottom than the top but not specifically in the centre

Wearb

powerade wrote: »

I think that they are all colder at the bottom than the top but not specifically in the centre

That's a typical sign of not enough heat being delivered to them.
To rule out sludge, turn off most but the coldest one on that zone to see if it heats up all over.
You could perhaps leave my suggestion until you exhaust the other previous advice, so as not to create confusion.

powerade

John.G. From what I can see, the bypass valve is fitted between the flow and return pipes. There is an arrow on the silver part of the valve connected to the flow pipe that points away from the flow pipe and there is a horizontal pipe running from the ABV to the return pipe. I hope that makes sense.

powerade

Wearb, thank you. I have all of the TRV's off the radiators now so I can't turn them off at the moment. I will check the radiators again when the heating fires up, especially those in Zone 2.

John.G

powerade wrote: »

John.G. From what I can see, the bypass valve is fitted between the flow and return pipes. There is an arrow on the silver part of the valve connected to the flow pipe that points away from the flow pipe and there is a horizontal pipe running from the ABV to the return pipe. I hope that makes sense.

Is the pipe approx 2 feet from the arrow (downstream) hot when all zones are open and the setting is 0.35? If so then it means that the circ pump is running with a head > 3.5M which should be adequate.

powerade

If I am facing the pipes, the vertical pipe on my left is the flow pipe(I think) and the vertical pipe on the right is the return. There is a gap of 7 inches between the two pipes which is bridged with the ABV and a copper pipe. The vertical copper pipe heats up immediately after I turn on any zone, regardless of the ABV setting.

powerade

I meant to say that the vertical return pipe and the horizontal pipe heat up immediately after I turn on any zone.

powerade

The only radiator that feels cooler at the bottom than the top when running at full temperature is the one in the kitchen and it is not a huge difference. I think the rest of the radiators are fine.

powerade

I have been doing a lot of research on Google into zone heating and by pass issues with WB Greenstar boilers. I also found the boiler manual which was very educational. One person had a problem getting the whole house to heat up. He lowered the maximum KW output on the boiler and cleaned the filter unit and his problem was resolved. That got me thinking as I could see from my manual that you could specify both a minimum and maximum KW output for my boiler. I calculated the approximate KW output of both zones, assuming that all of the radiators are fully turned on. The combined total is 14 kw. My boiler is a 25kw model and I am guessing that the maximum output is set to 25. I am wondeting if it would be more efficient to lower the maximum output to 15/16 and to set a minimum of 4. That should, in theory, allow me to turn off one of the radiators in Zone 2 and, hopefully, avoid cycling. Would this make sense? The second thing that I wondered about is the filter unit. When the plumber did the zoning work and put in the new pipes, he moved the filter unit to reside above the boiler connected to the return pipe. It transpires, however, that he positioned it upside down. Would that have any impact on the cleanliness of the system? He has agreed to call out next week, by the way, to balance the system, measure the temperature in all of the radiators, check the controls and flip the filter unit so that's quite a relief.
If changing the KW output settings of the boiler stops it from cycling, that will be a huge step forward but it still leaves me with the issue of the slowness of Zone 2 to heat, even when the boiler is not cycling. Perhaps that might be resolved when the system is balanced?

John.G

Have you got a link to your manual or is it a printed version you've got?.
Is the filter installed a simple Y strainer or is it a magnetic filter?.

powerade

It's a printed version John and the filter is magnetic

John.G

Since you have a users manual and though very very unlikely, can you check (as someone else suggested) that the flow and return pipework are connected as per that manual.
The default max/min output settings should be stated and possibly shows how to change them from a menu, 15kw/4kw sounds OK. The central heating settings can be changed without affecting the hot water output as you will need 25kw to give a reasonable showering flowrate of ~ 9/10 LPM.
The upside down filter, if magnetic only might not have much of a impact, apart from making it very messy if removing it to clean out, however, some also incorporate a strainer, which would make proper installation very desirable.

powerade

Thanks John. Checking the pipework is the next item on my list. There is a metal key which should be at the base of the filter and that needs to be removed in order to clean the filter. Given that it is currently on top of the unit, it is impossible to clean right now. Hopefully the plumber will sort that out next week. Interesting that you mentioned the hot water as I think there are issues with that too as the boiler goes straight into a HW anti rapid cycle as soon as the HW is turned on. Even if the HW is only on for a nano second, it takes forever for the heating to come back on and the temperature has to slowly climb back up again from around 42 degrees. I thought I would leave that, however, and focus on the central heating as that's complicated enough for me.

Dtp1979

I’m telling you again, for the 3rd time now there’s dirt in your system. On top of that, your radiators are too small in zone 2 or there’s no insulation. One last thing might be the boiler pump. As fancy and overpriced as WB boilers are, I’ve found a few pumps in the past to underperform like this.

powerade

With the greatest of respect, I don't think there is any issue with the size of the radiators as there was no issue heating Zone 2 prior to the heating being split into two zones. If anything Zone 2 was too warm as the digital thermostat was located in the living room in Zone 1 which is poorly insulated. Zone 2, on the other hand, has 82mm warm boards on the external walls and 1O0mm of soundproofing/heating insulation in the internal partitions/stud walls.WRT dirt in the system, how can I determine if that is the issue and why is it only impacting Zone 2?