I’m hoping someone may be able to point me in the right direction.

I’ve an old fashioned boiler and cylinder (unsealed) setup. Yesterday I started having issues in as much as it takes hours to heat the water, when the taps are turned on it takes much longer than normal to “pull” hot water through.

I’ve checked the boiler, output pipes are both hot, heating seems fine. Hot pipes by the cylinder are too hot to touch.

In the loft for other reasons this evening (starlings i think) and checked the header tank, the water in which was luke warm which surprised me “- i expected a little expansion into it but not enough to noticeably increase the temperature.

Is there anything obvious i should be checking? (there’s a pressure gauge on one of the pipes in the airing cupboard but i assume that’s for the heating?)

to me as a complete knowledgeless fool it’s almost as a valve has gone and I’m heating the header (which is in a cold loft and not exactly well insulated) and cylinder. It does get hot left looking enough so fairly sure it’s not the thermostat, it just takes about 3 hours instead of 15minutes or so.

Any help appreciated before i end up paying a plumber to turn a switch.

Cheers

when the boiler comes on, does a pump circulate the water throught he tank coil. The pump could have gone, heating the tank by gravity. the boiler would be cycling on, and off. Does this make sense?

It sort of does! I can’t hear a pump – i assume this would be in the boiler it’s self?

Could also be the coil in the cylinder leaking water across to the heating, but look for the obvious first such as pumps and motorised valves. However if the heating is working properly then pump is unlikely.
It could be a 3 port valve failed and not letting enough water through to heat cylinder efficiently.

Ta, sounds like a plumber then!

Interesting one….You say the main symptom is an excessively long time for the water to arrive at the hot outlet/s.
Firstly could it be the water is actually running slower? If so possibly a partial air-lock in hot pipe. Tap not opening fully. Filter in tap spout partly blocked.? If the pump had failed as already suggested you would have no heating, so assume pump is OK.
F/E Tank warm, fairly common actually, Could be pumping over vent pipe or gravity from cold feed. Various causes to be honest all down to poor design but if its only Luke warm not really a major problem. Possibly always done it and you haven’t noticed?
So… is the hot water flow rate noticeably reduced?

As per bear. 3 port valve issues (check the lever position) or HW internal coil leak.

If you have an open vented system. You would have 2 expansion tanks. One for your hot water cylinder and the other for the heating. They should not be combined in nearly all circumstances. There are exceptions to that which would complicate things further so I won’t bore you with complex musings. The fact you say there is a pressure gauge on the pipe work in the airing cupboard would indicate you have either a pressurised hot water cylinder, or a pressurised heating system.
Your lack of understanding of what you have, makes a request for diagnosis nearly impossible. There simply isn’t enough information provided.
My advice is to call someone who understands how systems work, and the difference between them. A heating engineer would be a good place to start as you have rightly suggested.

thanks for the pointers, booked a plumber any how but had a bit of a look see last night.

The heating pump is working best i can tell but is very hot to the touch, (sounds like it’s going all the time the heating is on though now that i know what I’m listening to) a bit of interwebbery suggests this shouldn’t be the case.

The pressure gauge reads bypass just underneath and its reading lower than I’d expect, at pure guess work, that it should. (Image below)

In terms of the draw through on the hot water the flow rate is good (its pumped), rather it takes about a mimute all of a sudden to start to be warm water. (Clearly it always had some lag between turning the tap on and the water running hot, just never that long)

Heating seems fine baring the kitchen radiator which seems very reluctant to warm up (this is a new problem) all other radiators in the house are possibly too hot.

I’m going to head up and have a look today but loft does indeed contain two tanks- one feed and one i assume expansion for the heating, the later has looked like it’s never seen any water in it’s life since i moved in 18 months ago so be interesting to see out it’s otherwise.

Again thanks for the pointers, it’s certainly going to be beyond my ability to fix by the sounds of it so no trouble with getting “a man in” jyst wanted to check out want likely to be a trip switch or something daft before i did.

That’s not a pressure gauge, it’s exactly what it says…. A bypass. Leave it alone and wait for your plumber.

Edit: Wait, what? there’s no water in the header tank? The ball valve has stuck up?
It’s sucking air perhaps. Yes, you need someone to look for you.
Incidentally, the pump should have an over run on it if the boiler is new/ish. This keeps it running for up to 10 mins or so after you switch the heating off. If it is constantly running the system is not wired correctly or there is a fault on one of the components.

Don’t worry no intention of fiddling beyond “ohhh that pipe is Hot”

Header tank i take to be the feed side. That’s fine though i did have to replace the inlet ballcock valve about 8 months ago.

The expansion tank looked like it’s been dry for ever last time i looked.

Pump goes off shortly after the heating sorry, just sounds to be running all the time the heating is “on”