Heating Lost Pressure

[clueless456]

Hi, I realise this is an electrical forum and not plumbing, but was wondering if somebody could help.

My heating is not working and the heating pressure guage has dropped to zero. The black valve you can see to the right of the photo cannot be turned and is locked in place. I cannot see any other valve, or screw to turn to increase the pressure back to normal. Should there be another valve switch somewhere?

Does anyone know what I can do to increase the pressure on the guage? I would really appreciate any help, as would prefer not to have to call out a heating engineer.

Many Thanks

 

[DPG]

The black tap will probably have seized due to lack of use. But if the pressure has dropped suddenly rather than just gradually over time, then it points to an issue somewhere in the system

 

[clueless456]

The black tap will probably have seized due to lack of use. But if the pressure has dropped suddenly rather than just gradually over time, then it points to an issue somewhere in the system

The black tap looks to be screwed in place with a little screw stopping it from moving. I haven't tried unscrewing it, as I assumed it was locked in place for a reason?

 

[DPG]

The black tap looks to be screwed in place with a little screw stopping it from moving. I haven't tried unscrewing it, as I assumed it was locked in place for a reason?

The screw just holds the plastic tap on to the metal spindle of the valve. Try again with more force. The worst that will happen is the black tap will spin and do nothing.

 

[clueless456]

The black tap will probably have seized due to lack of use. But if the pressure has dropped suddenly rather than just gradually over time, then it points to an issue somewhere in the system

Problem solved and pressure now sorted. The black tap was just stuck and extremely stiff, but just managed to turn it.

Thank you for speedy reply.

 

[DPG]

Problem solved and pressure now sorted. The black tap was just stuck and extremely stiff, but just managed to turn it.

Thank you for speedy reply.

Nice one. Keep an eye on the pressure over the next few hours/days to see if it starts dropping.

 

[clueless456]

Nice one. Keep an eye on the pressure over the next few hours/days to see if it starts dropping.

Thank you. The pressure has dropped a little since it was reset - What things could cause this? Could it be caused by having heating up too high / too many radiators on / radiators o too high etc?

Should the pressure always remain at the same level, or is it normal to go up & down?

 

[DPG]

Thank you. The pressure has dropped a little since it was reset - What things could cause this? Could it be caused by having heating up too high / too many radiators on / radiators o too high etc?

Likely a pressure leak somewhere. Either in the heating system itself, or somewhere in the pipes/radiators.

Someone with better plumbing knowledge than me will hopefully be able to help a bit more.

Pressure vessels in combi boilers often leak, bit I'm guessing that red tank in your picture is an external pressure vessel?

 

[littlespark]

Bleed the radiators, then up the pressure again.

Air inside the rads compress more than water.

 

[clueless456]

Likely a pressure leak somewhere. Either in the heating system itself, or somewhere in the pipes/radiators.

Someone with better plumbing knowledge than me will hopefully be able to help a bit more.

Pressure vessels in combi boilers often leak, bit I'm guessing that red tank in your picture is an external pressure vessel?

Thank you - I don't know if it's an external pressure vessel... I am a bit clueless with things like this.

 

[clueless456]

Bleed the radiators, then up the pressure again.

Air inside the rads compress more than water.

Thank you for the speedy replies. I'm sure I have a radiator key somewhere - It might be in a box somewhere in the garage.... I will try to find it.

 

[littlespark]

Bleed the rads when they’re cold.

Heating up the water increases pressure within the system anyway, but it expands into the air within the rads… and with the circulating pump running, it brings the overall pressure down.

If it’s like a combi boiler, optimum pressure should be between 1 and 2 bar when cold. Maybe a green mark on gauge showing good range.

 

[clueless456]

Bleed the rads when they’re cold.

Heating up the water increases pressure within the system anyway, but it expands into the air within the rads… and with the circulating pump running, it brings the overall pressure down.

If it’s like a combi boiler, optimum pressure should be between 1 and 2 bar when cold. Maybe a green mark on gauge showing good range.

Ok, thank you for the tip on bleeding them when cold. I have just ordered a radiator key, as not sure if I can find mine.

There is no green mark on the guage, but I reset it to the level marked on the bar which is set at just below 1.5... It has now dropped down to just below 1.

 

[James]

bear in mind that if you bleed air out of the radiators, the pressure will drop. you will have to add more water after bleeding to bring it up to the required pressure.

 

[nicebutdim]

Guage dropping to zero, then back from 1.5 Bar to 1.0 in a short space of time might be something more than air needing bled out of the system.

Is this the first time you've used the heating for some time or had it been working okay until recently?

 

[clueless456]

bear in mind that if you bleed air out of the radiators, the pressure will drop. you will have to add more water after bleeding to bring it up to the required pressure.

Thank you - I have never heard of having to top radiators up with water after bleeding bleeding before... Please could you provide clear instructions of how this is done, and how much water?

 

[clueless456]

Guage dropping to zero, then back from 1.5 Bar to 1.0 in a short space of time might be something more than air needing bled out of the system.

Is this the first time you've used the heating for some time or had it been working okay until recently?

It had been working fine before last night.

 

[James]

 

[nicebutdim]

Thank you - I have never heard of having to top radiators up with water after bleeding bleeding before... Please could you provide clear instructions of how this is done, and how much water?

You don't top up individual radiators, but the system (as you did earlier) as pressure may drop if quite a lot of air has to be bled from it.

It had been working fine before last night.

There may well be air needing bled from radiators, and this is definitely worth doing, but I suspect something more is at play. Sudden loss of all pressure and 1/3 additional loss a short time later isn't normal. It may be a cheap and simple fix, but more than likely it's time to call a plumber/heating engineer.

 

[clueless456]

You don't top up individual radiators, but the system (as you did earlier) as pressure may drop if quite a lot of air has to be bled from it.



There may well be air needing bled from radiators, and this is definitely worth doing, but I suspect something more is at play. Sudden loss of all pressure and 1/3 additional loss a short time later isn't normal. It may be a cheap and simple fix, but more than likely it's time to call a plumber/heating engineer.

Oh Ok, thank you, I understand. I will bleed the radiators first and see if there are any further problems first. I have the hot water switched on constantly sometimes - Could that maybe be the cause of the problem?

There has been an issue with low water pressure in the bathrooms since moving home - Could that also be due to the radiators needing to be bled?

If I made the pressure guage higher (such as 2, instead of 1.5), would that increase the water pressure in bathrooms?

 

[DPG]

Oh Ok, thank you, I understand. I will bleed the radiators first and see if there are any further problems first. I have the hot water switched on constantly sometimes - Could that maybe be the cause of the problem?

There has been an issue with low water pressure in the bathrooms since moving home - Could that also be due to the radiators needing to be bled?

The house water pressure won't affect your heating system pressure - they are not connected, apart from when you top up you heating system using the black filling valve.

 

[clueless456]

The house water pressure won't affect your heating system pressure - they are not connected, apart from when you top up you heating system using the black filling valve.

Ok thank you - Is there anything I can try to make the bathroom water pressure better?

 

[DPG]

Ok thank you - Is there anything I can try to make the bathroom water pressure better?

Might just be generally low in your area - speak to neighbours to see what theirs is like. If not then make sure your stoptap is fully open (but give it half a turn back in to prevent it sticking).

Sorry, is it just the bathroom? If so then do you have individual isolators for the taps?

 

[clueless456]

Might just be generally low in your area - speak to neighbours to see what theirs is like. If not then make sure your stoptap is fully open (but give it half a turn back in to prevent it sticking).

Sorry, is it just the bathroom? If so then do you have individual isolators for the taps?

When you say stoptap, do you mean the main water stopcock?

Yes just the bathrooms, the other sink taps in bathrooms and other areas of house have an ok pressure... There is an electric shower in the WC and another electric shower in en-suite, and the main bathroom has shower attachment to taps on the bath. Both of the electric showers have very poor water flow pressure, and the shower attachment on the bath taps is very poor pressure too.... The bath taps themselves and the sink taps are ok.... I have replaced the shower head on the bath with a new "power shower head", but still very poor water pressure through the shower heads.

I am not sure what you man about isolators for the taps? Do you mean electrical isolators?... The shower attachment attached to bath taps has a switch to alternate between taps & the show head. The other 2 showers are electric wall fitted shower units.

 

[littlespark]

He means something like a ball valve on the pipework that can shut off individual taps.

Your heating… the boiler, radiators and pressure vessel is a closed system that has nothing to do with the pressure at your taps and shower.

We do have a sister forum here so maybe register and ask the question there?

We’re clever, but we do like to let the plumbers answer a few questions now and again.

 

[DPG]

Might be worth changing one of the showers from an electric one to a mixer type fed from the combi. You will get better pressure and a much better shower.

I was meaning small isolators on the pipes feeding the taps - nothing electrical. Similar to the black one on your heating, but with a screw slot to operate.

 

[clueless456]

He means something like a ball valve on the pipework that can shut off individual taps.

Your heating… the boiler, radiators and pressure vessel is a closed system that has nothing to do with the pressure at your taps and shower.

We do have a sister forum here so maybe register and ask the question there?

We’re clever, but we do like to let the plumbers answer a few questions now and again.

Thank you - Is there any way you could tag other plumbers to save having to register on another forum?

 

[clueless456]

Might be worth changing one of the showers from an electric one to a mixer type fed from the combi. You will get better pressure and a much better shower.

I was meaning small isolators on the pipes feeding the taps - nothing electrical. Similar to the black one on your heating, but with a screw slot to operate.

It's a rented property, so I won't be spending any more than a few pounds for a new shower head (which i've already done) and will probably be moving home again in the near future.

I can't wash my hair properly because of the low shower pressure on the bath... Might be better washing/flushing my hair in the toilet, although come to think of it, the toilet flushing pressure is also poor.

Would the isolators for the pipes feeding the taps be in the same cupboard where the hot water tank is? I cannot see any other valves / taps / screw slots in there, other than the black tap for the pressure guage.

 

[nicebutdim]

Thank you - Is there any way you could tag other plumbers to save having to register on another forum?

It's a separate forum. We'd also have to register to post there.

 

[nicebutdim]

It's a rented property, so I won't be spending any more than a few pounds for a new shower head (which i've already done) and will probably be moving home again in the near future.

I can't wash my hair properly because of the low shower pressure on the bath... Might be better washing/flushing my hair in the toilet, although come to think of it, the toilet flushing pressure is also poor.

Would the isolators for the pipes feeding the taps be in the same cupboard where the hot water tank is? I cannot see any other valves / taps / screw slots in there, other than the black tap for the pressure guage.

Isolating valves for individual taps are typically located in the pipework close to the taps. Some may look like your mains stopcock, but generally they're small ball valves with a slotted head on the side which opens and closes with a quarter turn.

There are a number of reasons why bathroom water pressure is low, some of which could be related to water heating, but others entirely unrelated. At this point we'd be blindly firing possibilities at you and probably causing considerable confusion, just as a group of plumbers might if faced with electrical conundrums. Members on the plumbing forum will be able to ask pointed questions which hone in on the most likely causes of these problems.

 

[DPG]

Surely it's worth you taking a few minutes to create an account on a plumbing forum?

 

[brianmoooore]

A very common cause of pressure loss in the heating system is a leaking PRV (pressure release valve). That's the thing with the red conical knob, just behind the pressure gauge.
The copper pipe to the left of the PRV, running slightly downhill and then forwards, should go outside and have an open end, like an overflow pipe. If there is water occasionally dripping from it, then the PRV is the problem.

 

[littlespark]

If it’s a rented property, I’d report it to landlord and stop tampering with it.

You pay rent to them so they can keep the property maintained.

 

[DPG]

A very common cause of pressure loss in the heating system is a leaking PRV (pressure release valve). That's the thing with the red conical knob, just behind the pressure gauge.
The copper pipe to the left of the PRV, running slightly downhill and then forwards, should go outside and have an open end, like an overflow pipe. If there is water occasionally dripping from it, then the PRV is the problem.

Good shout. Can't believe I never thought of that, especially since I've had to replace the one on my previous boiler!

 

[clueless456]

Thank you again for the replies. So have found the problem - One of the bedroom radiators has a tiny pinhole leak from the pipe that leads to the radiator. The pipes leading to the radiators go along the wall beside the radiators and through the wall. From what I can see the leak is coming from one of the nuts on the pipe leading to the radiator.

I have wrapped the hole/leak with waterproof tape and wrapped a towel around it for now to try to stop the leak, and have turned off the heat control knob for that radiator. Is there anything else I can try to stop the leak - Should I try to tighten the nut where the leak is coming from? Or is there any other valve I can switch off somewhere on the radiator?

 

[DPG]

Thank you again for the replies. So have found the problem - One of the bedroom radiators has a tiny pinhole leak from the pipe that leads to the radiator. The pipes leading to the radiators go along the wall beside the radiators and through the wall. From what I can see the leak is coming from one of the nuts on the pipe leading to the radiator.

I have wrapped the hole/leak with waterproof tape and wrapped a towel around it for now to try to stop the leak, and have turned off the heat control knob for that radiator. Is there anything else I can try to stop the leak - Should I try to tighten the nut where the leak is coming from? Or is there any other valve I can switch off somewhere on the radiator?

Difficult to say. You could try tightening it, but don't over do it. Try and hold the radiator valve body with an adjustable spanner while you do it. The valve will have a flat section to allow this.

 

[brianmoooore]

It will probably cure it, but alternatively there's a chance it will make things worse.

 

[DPG]

Have a jug/bucket/cloths ready just in case. And an assistant!

 

[clueless456]

Difficult to say. You could try tightening it, but don't over do it. Try and hold the radiator valve body with an adjustable spanner while you do it. The valve will have a flat section to allow this.

The temperature control knob is on the opposite side of radiator. Does the other smaller knob, on opposite side to radiator have any purpose at all?

To try to tighten the nut on the pipe near the radiator, where the leak is coming from, do I turn the nut to the right, or the left? As do not want to loosen it by mistake.

 

[DPG]

The temperature control knob is on the opposite side of radiator. Does the other smaller knob, on opposite side to radiator have any purpose at all?

To try to tighten the nut on the pipe near the radiator, do I turn it to the right, or the left? As do not want to loosen it by mistake.

The valve on the other side is called a lockshield valve, and it is used when balancing the radiators so that they all give equal heat out. You wouldn't adjust it yourself.

The threads are standard right hand threads, so tighten as you would a normal nut on a bolt.

 

[clueless456]

The valve on the other side is called a lockshield valve, and it is used when balancing the radiators so that they all give equal heat out. You wouldn't adjust it yourself.

The threads are standard right hand threads, so tighten as you would a normal nut on a bolt.

I am not experienced with tightening nuts in general, but I do have a tool box... I do not want to cause a flood by loosening the nut.... Is it generally left for loose and right for tight?

 

[DPG]

I am not experienced with tightening nuts in general, but I do have a tool box... I do not want to cause a flood by loosening the nut.... Is it generally left for loose and right for tight?

Clockwise to tighten.

May be worth getting someone in to be honest. Not necessarily a plumber, but a decent handyman.

The risk is fairly small, but there is a chance things may go wrong.

 

[brianmoooore]

Most radiator valves have two nuts - one to the pipe and one to the radiator. Both are tightened clockwise when facing the valve.

 

[clueless456]

Here is a photo - The leaking nut is underneath the black tape. So facing the nut from the same angle the photo was taken, do I tighten it to the right, towards the wall?

Is there any way I can isolate the water flow to that pipe, without shutting off the water supply for entire house?

 

[littlespark]

RENTED!

Get the landlord to deal with it.

1. He pays
2. If it goes wrong, it his responsibility.

 

[clueless456]

RENTED!

Get the landlord to deal with it.

1. He pays
2. If it goes wrong, it his responsibility.

Thank you - Yes you are right, it is the landlords responsibility. But some landlords can get quite nasty with complaints about disrepair and sometimes results in retaliatory eviction...

Also, it takes time to arrange any professional to attend the property, and if it wasn't for the speedy replies on this forum encouraging me to try the black tap with more force, then I would have had no heating at all for at least another 1-2 days, which would have caused me huge problems due to severe health conditions.

If the problem is something simple that I might be able to rectify myself easily, with little cost, then I would prefer to do that. Having to call out a professional to the property, whether paid for by myself or the landlord, is also really inconvenient, as I also then have to block time off from work.

Maybe tightening the nut might not work, and I might have to report to landlord, but I would prefer to try, as it might rectify the problem.... Could anyone please just confirm which direction I should try to tighten the nut? As am worried about unscrewing it and causing massive flooding.

 

[littlespark]

righty tighty, lefty loosey


not all landlords are evil land barons... They might actually have a service plan in place that covers repairs

 

[DPG]

righty tighty, lefty loosey


not all landlords are evil land barons... They might actually have a service plan in place that covers repairs

Absolutely. Landlords seem to be a popular target of hate these days, but I could tell you a couple of stories about some interesting tenants!

 

[clueless456]

righty tighty, lefty loosey


not all landlords are evil land barons... They might actually have a service plan in place that covers repairs

righty tighty, lefty loosey


not all landlords are evil land barons... They might actually have a service plan in place that covers repairs

Sadly, in my personal experiences, 90% of landlords (and their managing agents) actually are.... Have been a landlord myself in the past and would never in a million years have ever treated my tenants the way I have been treated by some..

Righty tighty I will try...

 

[clueless456]

Absolutely. Landlords seem to be a popular target of hate these days, but I could tell you a couple of stories about some interesting tenants!

I am sure, but I could guarantee that as my experiences of a private tenant, I could absolutely trump those stories. The "rouge" landlords far outweigh the good ones unfortunately.