Vaillant boiler not heating radiators. Please help!

[Gasmk1]

sounds like the weather comp also its summer so it would run very low temp the only way to be sure is to remove the weather comp and run as normal boiler. as for rads fitted wrong some manufacturers put a small dimple in the header to let you know thats the bottom/top.

 

[Rystar00]

Thanks very much again guys. Will upload a pic of the install when I get home in half an hour.

To answer some of the questions:

1. I'm not sure if a bypass valve was fitted. It's an invented cylinder system. Will you be able to tell by the picture I will upload?

2. I turned the Internet off so it couldn't take data from the weather (put comfort override on which makes it operate according to the room stat). I put the room stat in the fridge to trick it into thinking it was cold. The flow temp reaches 75 degrees very briefly (less than 1 minute) and goes back down to 35 even though I'm asking for 30 degrees from the rads.

3. I have got the instructions for the radiators here. Will upload them and a pic of the rads. Silly question but is it possible to hang rads upside down (ie the flow and returns go where the air vent and blanking plug should be) as well as the flow and returns being in the wrong hole?

 

[ShaunCorbs]

Your rad instructions should tell you which way is best / any no nos

 

[Riley]

Thanks very much again guys. Will upload a pic of the install when I get home in half an hour.

To answer some of the questions:

1. I'm not sure if a bypass valve was fitted. It's an invented cylinder system. Will you be able to tell by the picture I will upload?

2. I turned the Internet off so it couldn't take data from the weather (put comfort override on which makes it operate according to the room stat). I put the room stat in the fridge to trick it into thinking it was cold. The flow temp reaches 75 degrees very briefly (less than 1 minute) and goes back down to 35 even though I'm asking for 30 degrees from the rads.

3. I have got the instructions for the radiators here. Will upload them and a pic of the rads. Silly question but is it possible to hang rads upside down (ie the flow and returns go where the air vent and blanking plug should be) as well as the flow and returns being in the wrong hole?

As far as I'm aware this boiler has an internal bypass

Has the heating ever worked? Do you get any errors at the boiler?

Yes it's possible but unlikely. Usually if manufacturers specify a way to pipe the rad they will add stickers or some sort of indicator

 

[quality]

does the vailliant system have a base setting for heat demand ?

 

[Rystar00]

Hi guys. Looks like the boiler is now firing up to full temp.

Have attached some pics to this post.

Some of the radiators (not all) are warming up but the heating has been running for 2 hours and I would expect them to be almost too hot to touch. Some are still stone cold (valves are open) and some which were previously hot are now cold! I'm so confused!

 

[Riley]

When was it installed???

 

[Rystar00]

Double post

It was fitted by the first plumber in September 2015 but not commissioned until 2 months ago. It was a long renovation,

Hot water been fine but heating always lukewarm

 

[ShaunCorbs]

by the looks of it rads installed wrong well going off instructions thats is

do a test

get the installer to turn hot water on (heat the cylinder) and manually open the two port to the rads (heating circuit) not via the head

does the heating work then?

 

[Stoney Ground]

First thing I would do would disconnect all controls and link out boiler to run totally independent, manually open heating zone valve.

Close all lock shield valves except furthest rad, check it heats up and identify F&R and if rad is piped as per instructions.

You could have 4 problems causing same effect
1. Rads piped wrong (shows top/bottom same end)
2. TRVs on return
3. Controls
4. Pump not man enough.

Solve each one in order, don't try to solve all at once.

Then repeat for next nearest rad, closing previous ones

 

[Rystar00]

Thanks very much guys. It's very kind of you to help

I have a vaillant engineer coming out on Saturday to rule out anything with the boiler. If it isn't the boiler I will show this thread to my installer.

Out of interest would it matter if the TRVs were on the returns if they're bi-directional please?

 

[Riley]

No if they are bidirectional that's what they're designed to do so it doesn't matter which pipe they are on

 

[Rystar00]

Thanks Riley.

Looks like I'm left to consider options 1 and 4 then (as vaillant replaced the controls last week)

 

[Riley]

Thank you for coming back please keep us posted

 

[Rystar00]

Hi guys,

Just thought I'd follow up.

Vaillant came out today and replaced the pump in the boiler. They said it was fine but would do it for free as a precaution. Unfortunately the rads are still not getting hot!

That leaves 2 issues - rads piped wrong or poor circulation. I think it's the latter because some of the rads have been piped correctly and none of them are getting hot (even the ones piped correctly).

Now I'm trying to find out who's fault this is. The first plumber ran the pipe work but the second plumber commissioned the boiler. Is it correct to assume that the person commissioning the boiler should have checked the heating before confirming it was ok to put carpets down?

In terms of my options I really don't want to rip all carpets and floorboards up and digging out the chases. Is it worth doing a power flush first? How effective are they normally? I'm hoping that because the first rad in the circuit is not getting hot that the blockage is early on in the circuit.

What would you guys do in my situation please?

Thanks

 

[Riley]

Sorry if this has been covered but I assume you've tried disconnecting a radiator and seeing if you get water out when heating is on? Is it warm?

 

[Riley]

Also are all you radiators the same

 

[Scott_D]

This is why noone want to take over from someone elses work

 

[Riley]

Exactly. I still reckon the problem lies with the rads or the TRVs

 

[Scott_D]

Did Vaillant charge for the two visits?
Has the heating zone valve been checked? whats on the pipe next to the zone valve for the heating?

 

[Riley]

Thanks Riley.

Looks like I'm left to consider options 1 and 4 then (as vaillant replaced the controls last week)

Also I thought you said that the valves weren't bi directional

 

[Riley]

Hi guys,

Just thought I'd follow up.

Vaillant came out today and replaced the pump in the boiler. They said it was fine but would do it for free as a precaution. Unfortunately the rads are still not getting hot!

That leaves 2 issues - rads piped wrong or poor circulation. I think it's the latter because some of the rads have been piped correctly and none of them are getting hot (even the ones piped correctly).

Now I'm trying to find out who's fault this is. The first plumber ran the pipe work but the second plumber commissioned the boiler. Is it correct to assume that the person commissioning the boiler should have checked the heating before confirming it was ok to put carpets down?

In terms of my options I really don't want to rip all carpets and floorboards up and digging out the chases. Is it worth doing a power flush first? How effective are they normally? I'm hoping that because the first rad in the circuit is not getting hot that the blockage is early on in the circuit.

What would you guys do in my situation please?

Thanks

If you're looking to blame, we don't know the full circumstance of your renovation.

Why did the first plumber not complete the job was there a falling out?
Yes the second plumber should've checked that the rads were heating up but was he working to your timescales was he under pressure to get done to a timescale?

It's difficult for us to comment

 

[Gasmk1]

the photo of the radiator shows it piped up as normal radiator but instructions say should be top and bottom if all rads are the same this may be your problem

 

[Rystar00]

Sorry for the late reply guys. I will try and answer your questions below!

1. I haven't tried disconnecting a radiator but they are all filled up (I've bled them all)

2. Some radiators are warm, some are stone cold (so not all the same)

3. I've checked the specs of the valves and they ARE bi-directional (sorry I'm a novice when it comes to plumbing)

4. I'm not looking to blame anyone for anything. I'm just trying to understand if it's customary for a plumber to check that the rads were operating properly when commissioning the boiler as we only laid the carpets when he said he'd commissioned it.

5. The first plumber was my child hood friend. Unfortunately we fell out as he prioritised other jobs after I'd paid him in full up front and left me in difficult situations with other trades when he kept failing to show up. I wish we'd never fallen out!

6. Vaillant didn't charge for the first visit as they replaced the controls which were faulty. They did charge for the second visit as they said the boiler is working fine but there is poor circulation in the system.

I'm in a tricky spot as everything has been plastered and flooring laid. I ran out of money (was messed about a few times by various trades) so had to try and finish stuff myself and I can't afford to rip everything up and start again

How effective would a power flush be at removing a blockage? I have uponor pipes everywhere apart from copper coming out of the boiler.

 

[Riley]

It doesn't sound to me like a blockage. I'd say more likely a piping issue

 

[Scott_D]

It sounds like plumber no 2 comissioned the boiler not the heating system

I doubt a power flush will do any good

Why not use some of that money to pay no 2 or someone new to come back and look at the heating system

 

[Rystar00]

Thanks again guys.

I'm out of pocket twice now (paid plumber 1 in full and he walked off before it was complete and plumber 2 obviously needed to make it worth his while). I'm now way over budget without a properly working system!

So would the person commissioning the boiler not check that the radiators pumped out heat please? Plumber 2 fitted the towel rails and they're not getting hot either.

 

[Riley]

It's likely a piping problem. Drain and remove one non working rad turn on heating and open each valve into a bucket is the water hot?

 

[Scott_D]

So would the person commissioning the boiler not check that the radiators pumped out heat please? Plumber 2 fitted the towel rails and they're not getting hot either.

In theory yes, but only you and he know what you agreed/paid for

 

[macackau]

4 storey house and a system boiler? I don't reckon the pump is up to it. Needs a bigger pump

 

[Rystar00]

Unfortunately I know nothing about plumbing so thought commissioning the boiler entailed checking that it actually caused heat to come out of the radiators. There is a danger if you spell things out to the nth degree that the installer thinks you're an idiot whereas I'm quite easy going and try to be nice to people.

I've just turned off all of the rads apart from the stone cold one. It made a big gurgling sound near the boiler and now some heat is slowly going to it.

What is the sound likely to mean please? Should I keep running the heating? I don't want to push the blockage further along out of reach and under the tiles by keeping it running!

I've bled the rad and warm water is coming out but not hot.

 

[Stoney Ground]

Now you've bled it check it stays warm, the gurgling noise will be air.

If it stays warm, then slightly open the next furthest Rad from the boiler and see how that does.

May need balancing to get an even heat distribution.

 

[Riley]

Did we get an answer???

 

[Rystar00]

Hi Riley,

Thanks for following up!

No update as of yet as the plumber hasn't been available. He is coming in to do a power flush on Thursday. I haven't got the skills to do what you suggested but bled the radiators and the water seems to be lukewarm even though the heating was on max for a couple of hours. What do you think that means please?

I obtained manufacturer instructions and some of the radiators (4 out of 12) can be piped either way and those aren't getting properly hot even with the others shut off so I'm not sure what the problem is.

I think it could be the pump not being up to the job (which is strange as the Vaillant engineer said it should be ok) or some sludge in the system.

I'm going to add some Sentinel x300 tonight and see if that improves things before the power flush is done on thursday. if that doesn't clear it up then will ask the plumber to fit a secondary pump.

If that doesn't work then I'm at a bit of a loss!

 

[Riley]

Have we definitely confirmed if valves are bidirectional