dan, is it possible to de scale as ive just looked at the price of a new one !
thanks, tim.
thanks, tim.
Pressure drops rapidly when boiler off
- Thread starter timritaharry
- Start date
Sponsored Links
http://www.thanetgasspares.com/prod...HW Heat Exchanger&cat=Ravenheat Boiler Spares
Not too bad I suppose... They can be done, but I don't think it is worth the ball-ache.
Not too bad I suppose... They can be done, but I don't think it is worth the ball-ache.
If it were my boiler, and I was able to do the job legally, I would descale the heat exchanger.
If you're able, and you have lots of time, and not much cash, it may be worth doing. Kilrock works well.
If you've got to call someone in, it wouldn't be worth descaling it, I shouldn't think.
We descale plate HEs, usually off site if we have a spare to change, and fit for £52 over our fixed price diagnostic charge.
The donut type, we descale in situ together with the rest of the boiler and charge £180. They are less prone to blocking compared with the plate with its very small water passages.
Tony
The donut type, we descale in situ together with the rest of the boiler and charge £180. They are less prone to blocking compared with the plate with its very small water passages.
Tony
Sponsored Links
ok, thanks again for everyones advice, tim.
pardon my ignorance but how come only the dhw is affected by the scale and not the central heating ?regards, tim.
There are two heat exchangers in most combi boilers - the main heat exchanger and the DHW heat exchanger.
In central heatiing mode the water is circulated through the main heat exchanger - where it picks up heat from the flame - and the radiators.
In hot water mode the diverter valve changes the flow so that the water circulates through the DHW heat exchanger instead of the radiators. This moves the heat between the system water, and the mains water for the taps - the two have to be kept separate.
If the DHW heat exchanger is dirty or scaled the heat can't get into the mains water quickly enough. This upsets the way the boiler works, usually with the result that the water from the tap will go hot-cold-hot-cold, or just be lukewarm.
if the heat exchanger was blocked would this not affect the flow of water at the tap ? theres no problem at all with the flow of water. its as if the tap water is getting too hot and the boiler shuts down till its cooled slightly and then starts up again it does this repeatedly.
- Joined
- 24 Dec 2019
- Messages
- 1
- Reaction score
- 0
- Country
My problem started due to pressure dropping, mainly when boiler was not in operation(heating off) and didn't seem to drop when the heating was on. I phoned the insurance company up who sent an engineer around who diagnosed a fault with the expansion vessel and also replaced the PRV. I would like to point out that the expansion vessel was faulty and full of water.
He went and yet the problem was still there(pressure dropping) and would go from 1.5 bar to around 0.3 bar over night. I than started pulling my house apart looking for a leak in the system, floor boards up the works. I was tossing and turning going out of my wits with worry due to a possibly hefty bill. After a month of worry I thought I would bleed the radiators and drain out the system, although the water was dirty I definitely had seen it worse in the past. I am not trying to plug a product here, I then put in 1litre of Sentinel X400. In order to drain the system properly, you need to open the bleeder valves when draining to let all water properly drain out before opening filling loop to run clean water through the system. Once the Sentinel x400 was in I topped the pressure back up, bled the radiators and then ran the heating until bedtime (21.00 hrs) no pressure drop. When I woke in the morning I checked the pressure, dropped yet again.i Topped back up for the wife and kids to get hot water and heating while I was at work. I phoned the insurance company up during the day and the engineer came around 17.00hrs and checked the pressure, no drop !. Boiler sorted, has been fine for days. In fact it's running like new.
He went and yet the problem was still there(pressure dropping) and would go from 1.5 bar to around 0.3 bar over night. I than started pulling my house apart looking for a leak in the system, floor boards up the works. I was tossing and turning going out of my wits with worry due to a possibly hefty bill. After a month of worry I thought I would bleed the radiators and drain out the system, although the water was dirty I definitely had seen it worse in the past. I am not trying to plug a product here, I then put in 1litre of Sentinel X400. In order to drain the system properly, you need to open the bleeder valves when draining to let all water properly drain out before opening filling loop to run clean water through the system. Once the Sentinel x400 was in I topped the pressure back up, bled the radiators and then ran the heating until bedtime (21.00 hrs) no pressure drop. When I woke in the morning I checked the pressure, dropped yet again.i Topped back up for the wife and kids to get hot water and heating while I was at work. I phoned the insurance company up during the day and the engineer came around 17.00hrs and checked the pressure, no drop !. Boiler sorted, has been fine for days. In fact it's running like new.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
