Pressure valve on Grant Module 50/70

bmaxi

I had to bleed two radiators and in the manual it says to adjust the pressure at the boiler but it also says there's an automatic air vent so I'm a bit confused. Now when I take the front panel off, I can see the burner and the thermostat but everything else is hidden behind insulation. Am I right in assuming the pressure relief valve is behind that insulation and is it ok to take it off, it seems to be all one piece? If and when I get to the valve do I turn it , push it, and what should the pressure be? Thanks.

cikearney

It is an AUTOMATIC air vent and there should be no need to do this. but sometimes they can be closed as they can leak.

Take the top cover off to access the AAV it should be located to the back of the unit, you should actually be able to reach your hand in to check the cap is open

shane0007

bmaxi wrote: »

I had to bleed two radiators and in the manual it says to adjust the pressure at the boiler but it also says there's an automatic air vent so I'm a bit confused. Now when I take the front panel off, I can see the burner and the thermostat but everything else is hidden behind insulation. Am I right in assuming the pressure relief valve is behind that insulation and is it ok to take it off, it seems to be all one piece? If and when I get to the valve do I turn it , push it, and what should the pressure be? Thanks.

If you have bled just 2 radiators your should not have to go near the boiler. Check your hotpress for the filling valve/loop to re-pressurise the system to between 1 and 1.5 bar when cold.

bmaxi

shane0007 wrote: »

If you have bled just 2 radiators your should not have to go near the boiler. Check your hotpress for the filling valve/loop to re-pressurise the system to between 1 and 1.5 bar when cold.

Where would they be in relation to the hot tank? I can't see anything in the hot press that looks like a pressure gauge so how would I know what the pressure is?

shane0007

Apologies, we should first establish if you have a pressurised system or an open vented system. Do you have a big tank and a little tank in your attic or just a big tank?
Do you have an expansion vessel anywhere on your system, such as in the hot press or at the boiler? It will look like a round red ball piped into the heating system.

bmaxi

shane0007 wrote: »

Apologies, we should first establish if you have a pressurised system or an open vented system. Do you have a big tank and a little tank in your attic or just a big tank?
Do you have an expansion vessel anywhere on your system, such as in the hot press or at the boiler? It will look like a round red ball piped into the heating system.

Yes, there's an expansion vessel in front of the hot tank but only one big tank.

shane0007

Ok it is pressurised so.

Is there a pressure gauge somewhere in the system? Likely places will be in the hot press or at the boiler.

bmaxi

Can't see anything in the hot press, wont be able to check the boiler until daylight as the only place a gauge could be is under the top panel and there's no light outside. and Mrs bmaxi has the car with the torch :mad: Will post then, thanks.

Billy Bunting

If you look around the boiler, it is likely to be in the panel on the back, 2 screws on the bottom.

shane0007

A Grant Module won't have it under the top panel. Just would not be enough room. It could be installed inside the back panel.
Saying that, it is an unlikely place to install it as mains water would have to run out to the boiler. I have seen it but very unusual.
What I am ultimately trying to get you to find is the filling valve/loop. This should be beside the pressure gauge. It is most likely to be in the hotpress as this is where you have both heating pipes and water mains.
Perhaps a photo of the hot press may be of benefit.

bmaxi

This enough? Not great at this uploading lark

shane0007

What about behind blankets/clothing? Also what about at higher level?

bmaxi

I was afraid you were going to say that. Hot press is choc-a-bloc with clothes, Mrs will have a seizure if I start to empty it now. I'll do it tomorrow and post then.

Billy Bunting

Whats over to the left ????

....

shane0007

bmaxi wrote: »

I was afraid you were going to say that. Hot press is choc-a-bloc with clothes, Mrs will have a seizure if I start to empty it now. I'll do it tomorrow and post then.

She'll be moaning more if she comes home to a cold house!

bmaxi

Turns out, as Billy Bunting said, relief valve is on back of boiler, very easily accessible when you take off the rear panel. It is presently at between .5 and .75 bar, do I twist it or lift it or push it, to what setting and if I overdo it, how do I correct that?

Billy Bunting

Although that is the presure gauge its attached to the PRV and it doesnt look like there is a filling loop in that location, a picture with more in it would help.
Did you check the hot press to the left as arrowed previously.

bmaxi

Billy Bunting wrote: »

Although that is the presure gauge its attached to the PRV and it doesnt look like there is a filling loop in that location, a picture with more in it would help.
Did you check the hot press to the left as arrowed previously.

Thanks for getting back, Ive cleared the hot press, is there enough detail in these? Do you need another pic of the boiler, there's not much more to see except the oil filler pipe, I think?

Billy Bunting

The nearest 2 gate valves upper left, are there open ???

bmaxi

Just noticed there is a valve on the top of the vertical pipe in picture 001 which has a pressure rating.

bmaxi

Billy Bunting wrote: »

The nearest 2 gate valves upper left, are there open ???

Yes, both are open.

shane0007

It looks like you have a system that is fed from your cwst!

The giveaway is the non-return on the pipe that coming from attic. That one is fed from the same pipe that is feeding your hw cylinder. This is a big no no. It is also why the pressure is a little low as it only have a gravity feed. If the non-return valve fails you will be showering in heating water and brushing your teeth in it too.

A simple fix. Disconnect and blank the tee from the cwst. Tee off mains going to cwst and fit a filling loop with a pressure gauge. Check non-return valve once removed to ensure it was working, otherwise you may have a fairly dirty system and may require a power flush.

spireland32

The 1st gatevalve at the front of your upper left side picture... that's the cold supply to your heating system. Once that's open your fine the system will top itself up and you can bleed your rads 1 or 2 times a year without a problem.

It's tee'd off the cold supply to your cylinder or cold to bathroom by the looks of it.
The system is filled from your domestic tank with a non return further down that half inch pipe which stops heating going back into your domestic water supply. Single non return valves do fail at some point however just so your aware.

shane0007

spireland32 wrote: »

The 1st gatevalve at the front of your upper left side picture... that's the cold supply to your heating system. Once that's open your fine the system will top itself up and you can bleed your rads 1 or 2 times a year without a problem.

It's tee'd off the cold supply to your cylinder or cold to bathroom by the looks of it.
The system is filled from your domestic tank with a non return further down that half inch pipe which stops heating going back into your domestic water supply. Single non return valves do fail at some point however just so your aware.

Snap!

bmaxi

shane0007 wrote: »

It looks like you have a system that is fed from your cwst!

The giveaway is the non-return on the pipe that coming from attic. That one is fed from the same pipe that is feeding your hw cylinder. This is a big no no. It is also why the pressure is a little low as it only have a gravity feed. If the non-return valve fails you will be showering in heating water and brushing your teeth in it too.

A simple fix. Disconnect and blank the tee from the cwst. Tee off mains going to cwst and fit a filling loop with a pressure gauge. Check non-return valve once removed to ensure it was working, otherwise you may have a fairly dirty system and may require a power flush.

Are you saying this is illegal or just bad practice? The house is only 7 years old would I have recourse to the builder to remedy this? Now you mention it, I remember my neighbour saying the water in his toilet cistern was warm, the plumbers made a big deal of it, said it would mean pulling up floorboards, never did hear the outcome but it could possibly be the same thing.

spireland32

It's "ok"...... put it on your to do list and get it changed at some point if it concerns you.

shane0007

Every one I come across, I change and many after I test has a stuck non return valve. For a small fix, I would get it done sooner rather than later. I have no idea whether it is illegal as you will not find it mentioned in any regulation but it is certainly very bad practice. It seems to be one of little inventions that we came up with to avoid call backs if we left a little leak, hmmm....

bmaxi

spireland32 wrote: »

It's "ok"...... put it on your to do list and get it changed at some point if it concerns you.

Thanks, I'd prefer if it wasn't fed from the cold water storage tank. Is it something I could tackle myself, not too flush ATM? If that NR valve was to fail is isolating it at that gate valve enough when changing it?

Billy Bunting

Gents, my eyes arn't the best in fact theyre crap so put this down to being sure, the second pipe along wouldnt be the heating vent ?? just my eyes seem to see a manifold below it, are we sure the furthest pipe isnt the cylinder cold feed ??

Combined feed and vent ?

shane0007

To be sure, follow the pipe with the non-return valve to the attic and see if it leads to the cwst, and see if it is also joining the heating system.

shane0007

Billy Bunting wrote: »

Gents, my eyes arn't the best in fact theyre crap so put this down to being sure, the second pipe along wouldnt be the heating vent ?? just my eyes seem to see a manifold below it, are we sure the furthest pipe isnt the cylinder cold feed ??

Combined feed and vent ?

It is difficult to see, but why would there be a vent in a pressurised system? I see where you are coming from though. It looks like the one with NR valve could go to vessel, but then why the NRV?

bmaxi

Billy Bunting wrote: »

Gents, my eyes arn't the best in fact theyre crap so put this down to being sure, the second pipe along wouldnt be the heating vent ?? just my eyes seem to see a manifold below it, are we sure the furthest pipe isnt the cylinder cold feed ??

Combined feed and vent ?

If a manifold means the same as in a car, i.e. one pipe with several running off it then yes.

Billy Bunting

shane0007 wrote: »

It is difficult to see, but why would there be a vent in a pressurised system? I see where you are coming from though. It looks like the one with NR valve could go to vessel, but then why the NRV?

Defo a strange one, it was the gate on what i thought was the vent that threw me, why! thats why i asked if they were open, all i could think is its been butchered over time one things for sure, my eyes see a monifold connected to the second pipe.

If the furthest pipe is followed and enters the cylinder at the bottom and has an mt cock then again it says cold feed.

shane0007

Have you another floor with rads?
Can you photo the expansion vessel pipe work?

bmaxi

shane0007 wrote: »

It is difficult to see, but why would there be a vent in a pressurised system? I see where you are coming from though. It looks like the one with NR valve could go to vessel, but then why the NRV?

The one with the NRV does go to the vessel.

Billy Bunting

bmaxi wrote: »

Just noticed there is a valve on the top of the vertical pipe in picture 001 which has a pressure rating.

Thats your PRV (presure relief valve) and is not to be tampered with, it should drain to low level but that doesnt look the case.

Billy Bunting

bmaxi wrote: »

The one with the NRV does go to the vessel.

You should also remove the head from this valve.......

bmaxi

Billy Bunting wrote: »

You should also remove the head from this valve.......

OK, can I ask why?

bmaxi

Billy Bunting wrote: »

Defo a strange one, it was the gate on what i thought was the vent that threw me, why! thats why i asked if they were open, all i could think is its been butchered over time one things for sure, my eyes see a monifold connected to the second pipe.

If the furthest pipe is followed and enters the cylinder at the bottom and has an mt cock then again it says cold feed.

The very furthest of the three pipes enter the tank at the bottom rear, there is a gate valve on it. It has never been touched since it was installed, that said this was in 2005 and the plumbing contractor had twelve guys working for him of whom I think two were actually plumbers, maybe this is normal in Poland.

Billy Bunting

That gate valve is acting as a balancing valve for your coil, once balanced (presuming) it should removed to prevent accidental tampering.

shane0007

shane0007 wrote: »

Have you another floor with rads?

Attic space with rad even?

bmaxi

shane0007 wrote: »

Attic space with rad even?

It's a two storey house, no extra rads fitted anywhere.

shane0007

Is the hot presss upstairs or downstairs?

bmaxi

shane0007 wrote: »

Is the hot presss upstairs or downstairs?

Upstairs.

shane0007

Ah jaysus, what are the pipes rising from the flow and return manifolds? I am baffled. Where do you live? I would nearly come round myself to have a gander as the interest is getting the better of me!!lol

spireland32

I think the two manifolds on the left are hots and colds...the 3/4 qualpex on the bottom of the tee is the main bathroom and half inch qualpex off the manifolds are en suites, kitchen (wash machine, dishwasher) downstairs toilet and wash basin, maybe even an outside tap.

If you look at the OP's 003 pix you can see it the expansion/hot off the cylinder. So now the picture with the gatevalves... 1st heating fill, 2nd cold to bathroom/sanitary, 3rd hot / expansion off cylinder with no valve, 4th supply to cylinder

shane0007

Of course!!! Thank you, thank you, thank you! No trip required. I can put back on my slippers.

Still fed from the tank though.

Billy Bunting

Sounds good to me.

Not easy following these pictures.

shane0007

Billy Bunting wrote: »

Sounds good to me.

Not easy following these pictures.

I blame you anyhow. Nobody mentioned manifolds..... LOL

bmaxi

shane0007 wrote: »

Of course!!! Thank you, thank you, thank you! No trip required. I can put back on my slippers.

Still fed from the tank though.

That's a pity, you could have had a trip to the sunny South East So are we going with the original diagnosis and remedy?

Billy Bunting

shane0007 wrote: »

I blame you anyhow. Nobody mentioned manifolds..... LOL

As i'm not a plumber i hadn't thought of manifolds on domestics.

I wonder if i can be a plumber if i get myself off on a weeks Chevron course