Intermittent heating from rads on ground floor - no issues with 1st floor

[tomatotomato]

Hope it's permissible to request some input here...

I live in a rented flat in London. We have two floors, ground and 1st, with radiator heating. The boiler is working fine (I believe) and we have plenty of hot water (radiator temp set at and hold at 73C). Four rads on the 1st floor are merrily putting out plenty of heat. Three of those four have TRVs on them, the other is "normal/manual" valve. On the ground floor we have two rads. One is TRV, the other is manual. The boiler is also on the ground floor.

We have always had issues with the rad in the dining room (manual). Until we turned the system down to leave for Xmas, the rad in the living room seemed fine. When I returned from Xmas, neither of the two were working. Again, 1st floor all fine. I called in the property agent's plumber yesterday, who indicated he adjusted one rad. Unfortunately I was at work so I don't know what exactly he did. When I got home, both rads were working.

This morning, once again, neither are working, and the air temp on ground floor is 14C (upstairs probably >20C). I can feel that the hot water line-in on both is cold. On the one in the living room, I can feel that it is at least warm about 7-8 ft from the rad, gradually growing cooler. I cannot do the same check for the one in the dining room as the line runs under the floor.

The valves on both are wide open (TRV on dining room is set to max/6). All I can guess is that something is preventing hot water from entering these rads. Obviously what the plumber did yesterday worked, but only temporarily.

What could this issue be caused by?

 

[SimonG]

Report to landlord and get them to sort it.

 

[tomatotomato]

Report to landlord and get them to sort it.

I appreciate the thought. The plumber that came yesterday was theirs. I would like to see if I can remedy it myself or at least get a lead on what's going on, as any plumber they send will not have the familiarity with the issue I do.

 

[Riley]

What boiler you got?
Have the rads ever worked properly?

 

[tomatotomato]

What boiler you got?
Have the rads ever worked properly?

Vaillant EcoTec 24 Pro.

They haven't worked properly since we moved in in November. For the majority of the time we've been here, the one in the living room has worked.

UPDATE: The one in the living room is working now, for whatever reason. I went out today and it was cold, came back tonight, hot. It is the one in the dining room that refuses to work.

 

[Harvest Fields]

I appreciate the thought. The plumber that came yesterday was theirs. I would like to see if I can remedy it myself or at least get a lead on what's going on, as any plumber they send will not have the familiarity with the issue I do.

A decent engineer will spend the time listening to the boiler/radiator issues that you have.

 

[tomatotomato]

A decent engineer will spend the time listening to the boiler/radiator issues that you have.

I'm certain that is true. However, I do not want to escalate this issue to my property managers again if it's a simple issue. On the other hand, if it's clearly a complicated one, I want to know that when I speak to them.

 

[Harvest Fields]

Can you take a picture of your timer and thermostat please.

 

[tomatotomato]

Certainly. Valves as well for good measure.

I've just noticed the clock on the boiler is wrong. However, it is set to "on", not timed mode, so I don't think it would matter? I haven't adjusted the clock and apparently neither did the plumber who was here yesterday. And of course the temp is controlled by the thermostat, which is set to go on to 19.5C in the morning and then down to 15C at bedtime.

 

[Harvest Fields]

Try setting it to manual and see if the rads get hot.

 

[tomatotomato]

All rads are hot except the one in the dining room. In fact our 1st floor bedrooms are probably over 20C right now. If my wife wasn't traveling she'd be making me open a window to sleep tonight.

 

[Harvest Fields]

Are both valves on that rad fully open?

 

[ShaunCorbs]

could be a balancing issue but best just pester the landlord

 

[tomatotomato]

Are both valves on that rad fully open?

Yes they are. And I've diddled with them a bit as well.

could be a balancing issue but best just pester the landlord

Quick Google suggests this may be exactly it. I'd try to get into it myself but the rads are old and painted over, and not even all the same, and I don't have many tools. Unless there's more advice to be had here I think it will probably have to be escalated again.

 

[Harvest Fields]

The only thing you could do. Is turn all the others off and run just that one for a couple of hours then turn the others back on one at a time until they start getting hot?

 

[tomatotomato]

The only thing you could do. Is turn all the others off and run just that one for a couple of hours then turn the others back on one at a time until they start getting hot?

To be clear, with the isolation/lockshield valves, right? Some have "innie" slot/blade screwdriver-style, not nibs/nipples like what I'm seeing on Youtube (I assume the newer style). I assume it's still a right to close, left to open thing. (Dumb questions but don't want to be mucking this thing up more.)

I should clarify that I come from a country where forced air heating is much more common than hot water... so these systems are pretty new to me.

 

[Harvest Fields]

Can you post another picture of what you mean

 

[ShaunCorbs]

sounds like iso valves

 

[tomatotomato]

Yup. Two pics of the isolator, one with cap, one without, plus one of the TRV, so you know what's on the other end. This is the one in the living room (working fine today). Several upstairs are similar. No nipples to twist.

 

[Harvest Fields]

How many Honeywell ones do you have?

 

[tomatotomato]

One. I also have a Drayton TRV, a Regis TRV, and a 4th that looks like the Honeywell but I'm not sure because it's somewhat hard to see (behind a chest of drawers).

Six rads total in the house. Four TRV. Two manual.

 

[Harvest Fields]

Turn the 4 trv off and leave the other two on.

 

[tomatotomato]

So before you made your last post, I went around and turned down, although not off, several of the TRVs. Lo and behold, it worked. The previously-cold rad is now putting out at least some heat. I am going to go and turn down the manual valve upstairs as well, since it's plenty warm up there.

Does this mean, basically, the boiler isn't of sufficient size, or the water flow through the house isn't efficient enough, to heat everything at once, so the hot water stalls in the system before reaching the badly-performing rad?

 

[Pickwickpick]

So before you made your last post, I went around and turned down, although not off, several of the TRVs. Lo and behold, it worked. The previously-cold rad is now putting out at least some heat. I am going to go and turn down the manual valve upstairs as well, since it's plenty warm up there.

Does this mean, basically, the boiler isn't of sufficient size, or the water flow through the house isn't efficient enough, to heat everything at once, so the hot water stalls in the system before reaching the badly-performing rad?

Sounds more like a balancing issue, so some rads are taking out too much heat and not leaving enough heat in the water for your problem rad. By balancing (i.e. in this case reducing) the flow through the other radiators your problem rad has heated up. With a bit more tweaking you should be able to get this to work properly.

 

[Pickwickpick]

There's a good guide to balance central heating here:

Croppie's Balancing Thread.

 

[tomatotomato]

Okay. Many thanks to all who provided constructive assistance in this thread! It is much appreciated.

 

[Pickwickpick]

Let us know how it goes.