damp stained lounge carpet - concrete floor

grumbler

homerhotspur said:

FreeBear said:

homerhotspur said:

whaThisIsWeird said:

Are you sure it's a solid concrete floor, or could it be a suspended concrete type? The latter certainly shouldn't have DPM issues as it won't have one. As I understand.

Looking more like a leaking CH. Does your boiler have a whatsit?

what is a whatsit?

Pressure gauge - Modern sealed boilers will have one, and should read somewhere around 1 to 1.5 bar in normal use. If your boiler is losing pressure, that indicates a leak somewhere in the system. If your CH pipes are running through the concrete floor and are copper, there is a chance there are pin hole leaks. Cement eats away at copper very slowly, and 25 years is about the time when problems start to occur. If it is a leaking copper pipe, tracing and fixing the leak is going to be expensive and messy. A short term fix might be to dose the system with Fernox F4 which might seal a leak for a year or two.

So, we would need to turn the CH on and then read the gauge?  

I don't think you need to turn it ON. It's under pressure regardless. The pressure dropping gradually indicates a leak somewhere.

FreeBear

No need to turn the CH system on. As long as it is pressurised, you should see the gauge move if there is a leak. But... Do be aware that the pressure will change slightly throughout the day due to changes in temperature - What you are looking for is a consistent drop in pressure over the course of days. So pump it up to say 1.5 Bar. If it has dropped to 1 bar after a week, you know there is a leak.

However, the leak could be in the expansion vessel or a faulty pressure relief valve in the boiler.

Currently pressure testing my heating system in preparation for a new boiler, so no EV or PRV to contend with. Seeing a 2-3 PSI (~0.2 Bar) variation due to temperature after 24 hours. As long as I don't see the pressure dropping by say 5 PSI (0.35 Bar) per day during the week, I'll be confident there are no leaks.

Not everyone will have a pressure gauge and suitable pump and are able to isolate a boiler from the CH system. So using the pressure gauge on the boiler is the next best thing. If it does indicate a leak, then time to call in the professionals - You might find it is covered under household insurance as "escape of water".

homerhotspur

grumbler said:

homerhotspur said:

FreeBear said:

homerhotspur said:

whaThisIsWeird said:

Are you sure it's a solid concrete floor, or could it be a suspended concrete type? The latter certainly shouldn't have DPM issues as it won't have one. As I understand.

Looking more like a leaking CH. Does your boiler have a whatsit?

what is a whatsit?

Pressure gauge - Modern sealed boilers will have one, and should read somewhere around 1 to 1.5 bar in normal use. If your boiler is losing pressure, that indicates a leak somewhere in the system. If your CH pipes are running through the concrete floor and are copper, there is a chance there are pin hole leaks. Cement eats away at copper very slowly, and 25 years is about the time when problems start to occur. If it is a leaking copper pipe, tracing and fixing the leak is going to be expensive and messy. A short term fix might be to dose the system with Fernox F4 which might seal a leak for a year or two.

So, we would need to turn the CH on and then read the gauge?  

I don't think you need to turn it ON. It's under pressure regardless. The pressure dropping gradually indicates a leak somewhere.

The gauge is towards the lowest end of the green range , about 1.3

homerhotspur

FreeBear said:

No need to turn the CH system on. As long as it is pressurised, you should see the gauge move if there is a leak. But... Do be aware that the pressure will change slightly throughout the day due to changes in temperature - What you are looking for is a consistent drop in pressure over the course of days. So pump it up to say 1.5 Bar. If it has dropped to 1 bar after a week, you know there is a leak.

However, the leak could be in the expansion vessel or a faulty pressure relief valve in the boiler.

Currently pressure testing my heating system in preparation for a new boiler, so no EV or PRV to contend with. Seeing a 2-3 PSI (~0.2 Bar) variation due to temperature after 24 hours. As long as I don't see the pressure dropping by say 5 PSI (0.35 Bar) per day during the week, I'll be confident there are no leaks.

Not everyone will have a pressure gauge and suitable pump and are able to isolate a boiler from the CH system. So using the pressure gauge on the boiler is the next best thing. If it does indicate a leak, then time to call in the professionals - You might find it is covered under household insurance as "escape of water".

The gauge I am looking at is on the ( top) water cylinder rather than the boiler itself , which doesn't have one

badger09

I hope for OP’s sake he doesn’t have underfloor CH leaks

We have a 1970s built, 1990s extended bungalow with concrete floors. We noticed rapid boiler pressure loss which several applications of sealant failed to fix. Specialist track & tracer company were unable to find the leaks, despite digging up some of our tiled floor. 

We definitely notice much greater pressure loss when CH is on for longer periods during autumn & winter. We’ve decided that even if one or more leaks could be traced, the chances of more occurring is too stressful to contemplate, so we’re having all the CH pipes rerouted above ground. Going to be expensive & disruptive, but at least we’ll be able to sleep at night & go away during the winter. Due to start work early next month. 

homerhotspur

badger09 said:

I hope for OP’s sake he doesn’t have underfloor CH leaks

We have a 1970s built, 1990s extended bungalow with concrete floors. We noticed rapid boiler pressure loss which several applications of sealant failed to fix. Specialist track & tracer company were unable to find the leaks, despite digging up some of our tiled floor. 

We definitely notice much greater pressure loss when CH is on for longer periods during autumn & winter. We’ve decided that even if one or more leaks could be traced, the chances of more occurring is too stressful to contemplate, so we’re having all the CH pipes rerouted above ground. Going to be expensive & disruptive, but at least we’ll be able to sleep at night & go away during the winter. Due to start work early next month. 

Thanks ( I think !)
I'm coming round to this being the most likely  cause. The thing that is confusing me is not seeing any evidence of actual moisture/ water anywhere other than soaked into the , now removed, underlay. Ive put the heating and water heater on but nothing has happened. Would this only happen when this is running? I'm now waiting for forecasted heavy downpours this afternoon, just in case it is anything to do with the water level under the floor?

victor2

 Now the damp areas are exposed, put some paper, like kitchen roll, down and you'll soon see if any liquid appears. Doesn't need your heating to be on, as the system is permanently pressurised, although the pressure does increase when the heating is running.

grumbler

homerhotspur said:

FreeBear said:

No need to turn the CH system on. As long as it is pressurised, you should see the gauge move if there is a leak. But... Do be aware that the pressure will change slightly throughout the day due to changes in temperature - What you are looking for is a consistent drop in pressure over the course of days. So pump it up to say 1.5 Bar. If it has dropped to 1 bar after a week, you know there is a leak.

However, the leak could be in the expansion vessel or a faulty pressure relief valve in the boiler.

Currently pressure testing my heating system in preparation for a new boiler, so no EV or PRV to contend with. Seeing a 2-3 PSI (~0.2 Bar) variation due to temperature after 24 hours. As long as I don't see the pressure dropping by say 5 PSI (0.35 Bar) per day during the week, I'll be confident there are no leaks.

Not everyone will have a pressure gauge and suitable pump and are able to isolate a boiler from the CH system. So using the pressure gauge on the boiler is the next best thing. If it does indicate a leak, then time to call in the professionals - You might find it is covered under household insurance as "escape of water".

The gauge I am looking at is on the ( top) water cylinder rather than the boiler itself , which doesn't have one

I'm no expert, but I don't understand this. If it's unvented system, hot water cylinder is under mains pressure. CH system, if unvented, doesn't have a cylinder, does it? Only the expansion vehicle.

homerhotspur

grumbler said:

homerhotspur said:

FreeBear said:

No need to turn the CH system on. As long as it is pressurised, you should see the gauge move if there is a leak. But... Do be aware that the pressure will change slightly throughout the day due to changes in temperature - What you are looking for is a consistent drop in pressure over the course of days. So pump it up to say 1.5 Bar. If it has dropped to 1 bar after a week, you know there is a leak.

However, the leak could be in the expansion vessel or a faulty pressure relief valve in the boiler.

Currently pressure testing my heating system in preparation for a new boiler, so no EV or PRV to contend with. Seeing a 2-3 PSI (~0.2 Bar) variation due to temperature after 24 hours. As long as I don't see the pressure dropping by say 5 PSI (0.35 Bar) per day during the week, I'll be confident there are no leaks.

Not everyone will have a pressure gauge and suitable pump and are able to isolate a boiler from the CH system. So using the pressure gauge on the boiler is the next best thing. If it does indicate a leak, then time to call in the professionals - You might find it is covered under household insurance as "escape of water".

The gauge I am looking at is on the ( top) water cylinder rather than the boiler itself , which doesn't have one

I'm no expert, but I don't understand this. If it's unvented system, hot water cylinder is under mains pressure. CH system, if unvented, doesn't have a cylinder, does it? Only the expansion vehicle.

No expert either. I can only tell you there is one very big white cylinder with  2 much smaller ones above, one red and one white and on top of the red one is the gauge, which I have just topped up to 1.6 to monitor.

grumbler

The smaller red one is the expansion vehicle for CH system.